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A  PRACTICAL  TREATISE 


Artificial  Crown-  and  Bridge- Work 


PORCELAIN  DENTAL  ART. 

BY 

GEORGE   EYAIvTS, 

LECTUEBE  ON  CROWN-  AND  BRIDGE-WORK  IN  THE  BALTIMORE   COLLEGE  OF  DENTAL  SURGERY  : 
CLINICAL    LECTURER    IN    THE    NEW   YORK    COLLEGE    OP    DENTISTRY;    MEMBEE   OF   THE 
NATIONAL  DENTAL  ASSOCIATION  ;   OF  THE  SOUTHERN  BRANCH  OF  THE  NATIONAL 
DENTAL  ASSOCIATION  ;   OF  THE  DENTAL   SOCIETY  OF   THE  STATE  OF  NEW 
YORK  ;    OP  THE    FIRST  DISTRICT  DENTAL  SOCIETY  OF  THE   STATE 
OP     NEW    YORK  ;    OP    THE    NEW    YORK    ODONTOLOGICAL 
SOCIETY;    HONORARY    MEMBER    OP    THE    MARY- 
LAND STATE  DENTAL  ASSOCIATION,  ETC. 

Sixth  Edition,  Revised. 


WITH    6S1    ILLUSTRATIONS. 


PHILADELPHIA: 

THE  S.  S.  WHITE  DENTAL  MFG.  CO. 

1900. 


iqoo. 


Copyright,  1888,  by  George  Evans. 
Copyright,  1889,  by  G-eoege  Evans. 
Copyright,  1893,  by  George  Evans. 
Copyright,  1893,  by  George  Evans. 
Copyright,  1896,  by  George  Evans. 
Copyright,  1 900,  by  George  Evans. 


HE  PATTERSON   AND  ' 


To  the  Members 

of  the 

First  ^District  (Dental  Society  of  the  State  of  J^ew  York^ 

this  (Book  is  respectfully  dedicated 

by 

Tee  piETEDR. 


PREFACE  TO  SIXTH  EDITION. 


Twelve  years  have  elapsed  since  the  first  edition  of  this  book 
V7as  presented  to  the  dental  profession.  During  that  time  several 
successive  revisions  have  been  made  to  better  adapt  it  to  meet  the 
requirements  of  a  practical  treatise  for  college  and  post-graduate 
study,  and  of  a  book  of  reference  for  the  practitioner.  The  en- 
deavor has  been  at  all  times  to  make  the  text  comprehensive  with- 
out being  bulky,  and  concise  without  sacrificing  cl earner  for 
brevity.  Descriptions  of  rarely  practiced  or  unimportant  methods 
have  been  curtailed  from  time  to  time,  obsolete  matter  omitted, 
and  repetition  avoided  as  much  as  possible. 

Practitioners  of  to-day  seek  methods  which  mil  permit  the  at- 
tainment of  the  desired  results  in  crown-  and  bridge-work  without 
the  devitalization  of  pulps,  with  the  least  possible  mutilation  of 
the  natural  teeth,  and  the  smallest  exposure  of  metal,  and  which 
are  least  complex  in  construction. 

These  ideas  have  largel}^  influenced  the  conduct  of  the  revision 
of  this  edition.  Many  changes  have  been  made  in  the  text  by  the 
elimination  of  old  matter  and  the  introduction  of  new  in  the 
description  of  methods  and  details  of  construction.  Some  spe^ 
cial  methods  of  little  general  service  in  crown-  and  bridge-work  are 
still  presented  because  they  may  occasionally  furnish  suggestions 
for  construction  by  which  some  existing  obstacle  or  difficulty  can 
be  readily  overcome. 

Crown-  and  bridge-work,  having  been  fully  recognized  as  a  legit- 
imate branch  of  dental  prosthesis,  is  listed  as  a  special  branch  in  the 


Vi  PREFA  CE. 

curriculum  of  every  dental  college.  In  application  it  approaches 
a  fine  art.  In  no  branch  of  dentistry  will  lack  of  knowledge  and 
skill  or  the  exhibition  of  carelessness  in  constructive  details  be 
more  plainly  evidenced,  or  result  in  greater  proportionate  injury 
instead  of  benefit.  Criticism  of  failures  should  therefore  be  gov- 
erned by  these  considerations.  Many  failures  are  to  be  attribiited 
to  attempts  to  perform  bridge-work  operations  with  about  the 
same  expenditure  of  time  on  'the  part  of  the  dentist  and  money 
on  the  part  of  the  patient  as  in  plate-work.  There  is  no  such  rela- 
tion between  these  two  methods  of  procedure. 

The  advances  in  porcelain  inlays  and  porcelain  bridge-work 
have  been  so  conspicuous  during  the  past  year  or  two  that  it  has 
been  deemed  desirable,  in  order  that  they  might  be  properly  pre- 
sented, to  give  them  a  distinct  classification  under  the  title,  "Por- 
celain Dental  Art." 

Acknowledgment  is  specially  made  by  the  author  to  Dr.  F.  J. 
Capon,  of  Toronto,  Canada,  for  suggestions  on  porcelain  crown- 
work,  personally  given;  to  the  writings  of  Dr.  C.  L.  Alexander, 
of  Charlotte,  N^.  C,  on  crown-  and  bridge-work,  in  the  Dental 
Cosmos;  to  Dr.  W.  H.  Taggart  and  Dr.  H.  J.  Goslee,  of  Chicago, 
papers  and  discussions  on  porcelain  bridge-work  in  the  Dental 
Review;  to  Dr.  J.  L.  Williams,  of  London,  Eng.,  and  Dr.  Joseph 
Head,  of  Philadelphia,  writings  on  porcelain  inlays  in  the  Dental 
Cosmos;  to  Dr.  W.  A.  Capon,  of  Philadelphia,  for  suggestions 
personally  given  and  writings  on  porcelain  dental  art;  Dr.  'N.  S, 
Jenkins,  of  Dresden,  Germany,  for  personal  suggestions  and  writ- 
ings on  porcelain  inlays. 

Geoege  Evans. 
65  West  39th  St.,  New  York. 

August  27,  ]  900. 


CONTENTS. 


PAGE 

Introduction 1 

Artificial  Crown-  and  Bridge-Work 5 

PAET   I. 

PREPARA.TORr    TREATMENT    OF    TEETH    AND    ROOTS    FOR    CROWN-WORK. 

CHAPTER    I. 

The  Pulps  of  Teeth — Their  Preservation  or  Devitalization — Pulp- 
Capping , 10 

CHAPTER   II. 
Devitalization  of  the  Pulp 15 

CHAPTER   III. 

PuLPLESs  Teeth — Preparation  of   Root-Canals — Their  Treatment, 
Disinfection,  and  Filling 19 

CHAPTER   IV. 
Chronic  Alveolar  Abscess 30 

CHAPTER   V. 
Shaping  Teeth  and  Roots  for  Crown-Work 35 

PART   II. 

ARTIFICIAL    CROWN-WORK. 

the  porcelain  system. 

CHAPTER   I. 

Porcelain  Crowns 44 

The  Gates-Bonwill  Crown 45 

The  Poster  Crown 49 

The  Howland-Perry  Crown 49 

The  Logan  Crown 50 

Remarks  on  the  Use  of  P.jrcslain  Crowns  and  Crowns  without  Cellars...  57 

vii 


^jlj  CONTENTS. 

CHAPTER   II. 

PAGE 

Porcelain  Crown  with  Gold  Collar  Attachment 58 

Method  of  Mounting  a  Logan  Crown  with  a  Band  and  Cap 69 

CHAPTER   III. 

Porcelain  Crowns  with  Rubber  or  Vulcanite  Attachment 6& 

THE   gold    system. 

CHAPTER   IV. 

Gold  Collar  Crowns 66 

The  Construction  and  Adaptation  of  Collars 66 

Collar  Crowns  Hygienically  Considered TS 

CHAPTER   V. 

Gold  Collar  Crowns  with  Porcelain  Fronts 74 

Incisors  and  Cuspids 74 

Bicuspids  and  Molars 78' 

CHAPTER   VI. 

All-Gold  Collar  Crowns  for  Bicuspids  and  Molars  constructed 
IN  Sections 8S 

CHAPTER   VII. 

The  Gold  Seamless  Cap-Crown 93 

Incisors,  Cuspids,  and  Bicuspids,  with  Porcelain  Fronts 93 

Ail-Gold  Seamless  Bicuspids  and  Molars 95. 

CHAPTER   VIII. 

Gold  Seamless  Contour  Crowns 99 

Adjustment  of  Seamless  Contour  Crowns 102 

CHAPTER   IX. 

Special  Forms  of  Gold  Crowns  with  Porcelain  Fronts ill 

Porcelain  and  Gold  Crown  without  a  Collar,  and  Partial  Collar  Crowns.  Ill 

Mounting  the  Porcelain  Front II5 

The  Parr  Crown Hg 

The  Leech  Crown jjir 

The  Perry  Crown Hg 


CONTENTS.  ix 

CHAPTER   X. 

PAGE 

Crowning    Fractured    Teeth    and   Roots — Crowning    Molar    Roots 

DECAYED    APART    AT     BIFURCATION CROWNING     IN    CaSES     OF     IRREGU- 
LARITY    120 

Longitudinal  Fracture  of  the  Crown  and  Root 120 

Fracture  of  the  Crown  with  Slanting  Fracture  of  the  Root 121 

Perforation  of  a   Side- Wall  of    a  Root-canal   or  of  the  Dentin  at  the 

Bifurcation  of  the  Roots 122 

Crowning  Molar  Roots  decayed  apart  at  the  Bifurcation 123 

Dr.  Farrar's  Cantilever  Crown 123 

Methods  of  Crowning  in  Cases  of  Irregularity 124 

CHAPTER   XI. 
Partial  Crowns 125 

CHAPTER   XII. 

Finishing  and  Polishing — Process  of  Cementation 133 

Finishing  and  Polishing  Crown- Work 133 

Insertion  and  Cementation 133 

Oxyphosphate  of  Zinc 133 

Gutta-Percha 137 

Amalgam 141 

PAET   III. 

BRIDGE-WORK. 

CHAPTER    I. 
Construction  of  Bridge-Work 1-50 

CHAPTER   II. 
Special  Processes  and  Appliances  in  Bridge- Work 163 

CHAPTER   III. 
Extension   Bridges 172 

CHAPTER  IV. 
Bar  Bridges 178 

CHAPTER  V. 
Partial  Cap  and  Pin  Bridge 183 

CHAPTER  VI. 

Removable  and  Replaceable  Porcelain  Fronts 186 


^  CONTENTS. 

CHAPTER   VII. 

PAGE 

General  Application  or  Crown-  and  Bridge-Work 189 

Extensive  Applications  of  Crown-  and  Bridge-Work 200 

CHAPTER   VIII. 

208 
Repair  of  Crown-  or  Bridge-Work 

CHAPTER   IX. 

The  Hygienic  Condition  of  the  Mouth  as  affected  by  Bridge-Work  214 

CHAPTER   X. 

Removable  and  Detachable   Bridge-Work 216 

Removable  Incisor  or  Cuspid  Crown 

Removable  Bicuspid  and  Molar  Attachments 

CHAPTER  XI. 

234 
Removable  Plate  Bridges 

CHAPTER  XII. 

Special  Forms  of  Detachable  and  Removable  Bridge-Work 246 

Dr.  Winder's  Sectional  Crown  Method 

Dr.  Litch's  Method 

Dr.  R.  W.  Starr's  Methods ^^^ 

Dr.  Parr's  Methods ^gg 

Dr.  Waters's  Methods 

Dr.  Bonwill's  Method 

CHAPTER   XIII. 

„       ^  -269 

Removable  Bar-Bridges 

CHAPTER    XIV. 

275 
Dr.  Knapp's  Methods 

CHAPTER   XV. 

280 

The  Mandrel  System 

CHAPTER   XVI. 

287 
The  HoLLiNGSwoRTH  System 

To  Make  a  Gold  Crown  (Bicuspid  or  Molar) ^»^ 

To  Make  Solid  Gold  Cusps •• 

To  Make  Gold  Crowns  (Centrals,  Laterals,  and  Cuspids) ^^J 

To  Insert  a  Porcelain  Facing ;•; 

To  Make  the  Grinding-Surface  of  a  Bridge  in  One  Continuous  Piece 294 

Facings  for  Making  All-Gold  Bridge '^ 

CHAPTER   XVII. 
Crown-  and  Bridge-Work  combined  with  Operative  Dentistry  in  ^^^ 
Dental  Prosthesis 


CONTENTS.  xi 
PAET   IV. 

PORCELAIN    DENTAL    ART. 
CHAPTER   I. 

PAGE 

Porcelain  Inlays 310 

Preparation  of  Cavities 311 

To  Form  the  Matrix 314 

Investing  the  Matrix 317 

Selecting  the  Color  of  the  Porcelain  Body 318 

Dr.  Jenlcins's  Low-Fusing  Porcelain  319 

High-Fusing  Porcelain 321 

Removing  the  Foil  Matrix 321 

Cementation 322 

Points  to  Bear  in  Mind 322 

Porcelain  Tips 325 

CHAPTER   II. 

Porcelain  and  Platinum  Crowns 327 

Porcelain  Inlaying  of  Gold  Crowns 331 

Respective  Merits  of  Various  Grades  of  Porcelain 333 

CHAPTER   III. 

Porcelain  Bridge-Work 335 

Platinum  Solder 341 

Furnaces  for  High-Fusing  Porcelain 342 

PAET   V. 

MATERIALS   AND    PROCESSES    USED    IN    CROWN-   AND    BRIDGE-WORK. 

CHAPTER  I. 

Plates  and  Solders 347 

CHAPTER  II. 

Porcelain  Teeth 351 

CHAPTER   III. 

Molds  and  Dies 362 

How  to  Quickly  Make  a  Tube  and  Fusible  Metal  Die 352 

CHAPTER   ly. 

Soldering 354 

CHAPTER  V. 

Instruments  and  Appliances 357 

Index , 361 


INTEODUOTIOISr  TO  FIRST  EDITIOK 


Of  the  origin  of  the  art  of  dentistry  no  one  can  speak  with 
certainty,  as  its  early  history  is  shrouded  in  the  mists  of  antiquity ; 
but  dental  operations  are  recorded  in  very  remote  times. 

References  are  made  to  the  art  in  the  writings  of  Hippocrates, 
in  the  fifth  century  b.c.  Martial,  the  Latin  poet,  in  the  first 
century  b.c,  says  that  a  Roman  dentist  "Cascellius  is  in  the  habit 
of  fastening  as  well  as  extracting  the  teeth."  To  Lelius  he  says, 
"You  are  not  ashamed  to  purchase  teeth  and  hair;"  and  adds  that 
"the  toothless  mouth  of  Egle  was  repaired  mth  bone  and  ivory;" 
also,  that  "Galla,  more  refined,  removed  her  artificial  teeth  during 
the  night." 

Horace,  in  the  same  century,  cites  the  case  of  the  "sorceresses 
Canidia  and  Sagana  running  through  the  city  and  losing  the  one 
her  false  hair,  the  other  her  false  teeth." 

Gralen,  the  celebrated  physician,  in  the  second  century  a.d., 
also  speaks  of  the  art  of  dentistry  as  being  then  practiced. 

These  early  operations  were  limited  to  the  extraction  of  offend- 
ing teeth  and  the  replacement  of  those  which  had  been  lost  with 
fc^ubstitutes  which  were  retained  in  position  by  means  of  narrow 
bands  or  ligatures  attaching  them  to  the  adjoining  natural  teeth, 
ji.nd  without  the  use  of  plates.  Crude  as  they  were,  they  formed 
the  first  expression  of  the  art  of  dentistry,  a  beneficent  art  from 
the  beginning,  in  that  it  sought  to  remedy  pathological  or  acciden- 
tal defects.  Confined  to  the  simplest  operations,  it  existed  for 
centuries,  and  then  was  apparently  lost  during  the  Dark  Ages,  to 
reappear  when  the  more  general  diffusion  of  knowledge  ushered 
in  the  modern  era  of  science  and  invention. 

After  its  revival,  dentistry,  so  much  of  it  as  was  known,  was 
in  a  measure  a  secret  art,  the  practice  of  which  even  within  the 
memory  of  men  now  living,  and  they  not  the  oldest,  was  involved 

2  1 


2  INTRODUCTION  TO  FIRST  EDITION. 

in  mystery;  but  recent  progress. has  lifted  the  veil,  and  dentistry, 
in  the  treatment  of  the  teeth  on  correct,  scientific,  rational  prin- 
ciples, has  developed  an  art  and  a  science  which  have  given  it 
honorable  rank  among  the  professions.  In  its  twofold  evolution 
it  has  absorbed  from  every  available  source  whatever  would 
broaden  its  science  or  perfect  its  art.  It  calls  to  its  aid  anatomy, 
physiology,  pathology,  chemistry,  therapeutics,  metallurgy,  sculp- 
ture, and  mechanics,  with  each  of  which  it  stands  in  closer  or  more 
remote  relation;  and  the  practitioners  of  dentistry  who  have  be- 
come the  most  eminent  and  useful  have  been  men  of  broad  attain- 
ments and  great  versatility  of  talent. 

In  the  history  of  all  progress,  movements  apparently  of  a  more 
or  less  reactionary  character  are  recorded.  In  the  useful  arts 
especially  it  is  not  uncommon  to  find  a  return  to  forms  and 
methods  form.erly  used,  but  long  since  discarded  and  forgotten. 
So  in  dentistry  we  find  methods  of  treatment  and  modes  of  practice 
once  in  vogue  but  long  fallen  into  disuse,  revived  with  improve- 
ments and  modifications  that  stamp  them  as  practically  redis- 
coveries. 

These  movements  are  not  to  be  regarded  as  retrogressive, 
because  the  modifications  which  accompany  the  reintroduction  of 
practical  ideas  and  inventions  attest  them  as  real  advances,  and 
indicate  clearly  that  the  cycle  of  knowledge  is  ever  widening  with 
experience.  This  volume  demonstrates  how  modern  dentistry 
has  utilized  the  principles  of  some  of  the  simplest  original  opera- 
tions, and  by  "proving  all  things,  holding  fast  that  which  is  good.'^ 
has  attained  its  present  honorable  position  in  both  its  scientific  and 
artistic  departments. 

The  history  of  dentistry  of  later  years  is,  in  brief,  a  recital  of 
progress  and  improvement.  The  medical  profession  has  officially 
recognized  it  as  closely  allied  to  medicine  by  inviting  its  represen- 
tatives to  take  part  in  the  International  Medical  Congresses  on  the 
footing  of  professional  equality. 

Such  is  the  position  which  dentistry  has  attained.  Much  of 
the  progress  which  has  made  its  present  elevation  possible  must 
be  credited  to  the  dental  profession  of  the  United  States,  which 


IJSTROVUCTION  TO  FIRST  EDITION.  3 

lias  been  justly  termed  the  cradle  of  modern  dentistry.  Here 
the  validity  of  the  idea  that  scientific  knowledge  should  form  the 
basis  of  training  for  practice  was  first  demonstrated  by  the  success- 
ful establishment  of  dental  schools;  here  the  first  journal  for  the 
interchange  among  dentists  of  thought  and  experience  was 
founded;  here  the  first  association  having  for  its  object  the  uplift- 
ing and  upholding  of  dentistry  by  the  mutual  helpfulness  of  its 
practitioners  had  its  origin;  here,  in  a  word,  dentistry  was  first 
divorced  from  mystery,  here  it  first  passed  the  narrow  confines  of 
a  mere  handicraft  and  earned  for  itself  the  right  to  be  classed 
among  the  learned  and  liberal  professions. 


ARTIFICIAL  CROWN-  AND  BRIDGE-\YORK. 


Modern  artificial  crown-  and  bridge-work  belongs  to  the 
department  of  dentistry  formerly  termed  "mechanical;"  but  the 
judgment,  skill,  and  scientific  information  required  place  it  far 
above  ordinary  mechanical  dentistry,  which  has  sunk  to  a  low 
estate  since  the  introduction  of  vulcanite.  To  such  an  extent  has 
vulcanite,  by  reason  of  its  cheapness  and  ease  of  manipulation, 
superseded  other  materials  demanding  greater  knowledge  and 
skill  in  their  manipulation,  as  to  retard  the  higher  development 
of  prosthetic  dentistry,  and  indeed  to  divest  it,  in  the  hands  of 
those  who  depend  upon  vulcanite,  of  the  dignity  which  should 
belong  to  dentistry  as  a  profession. 

But  modern  crown-  and  bridge-work,  properly  understood  and 
properly  performed,  takes  high  rank  in  dental  art,  and  offers  wide 
scope  for  versatiHty  of  tale^it  and  inventive  genius.  The  varied 
and  complicated  cases  presenting  for  treatment  frequently  suggest 
to  the  expert  novel  contrivances  and  methods  of  construction  and 
application.  Successful  practice  of  crown-  and  bridge-work 
depends  upon  a  thorough  mastery  of  the  underlying  principles, 
and  expertness  in  the  processes  involved,  governed  by  sound  judg- 
ment and  perfect  candor.  The  interests  of  the  patient  should  be 
paramount  to  every  other  consideration,  and  after  a  careful 
examination  he  should  be  given  an  accurate  statement  of  the 
applicability  of  the  system  to  his  case,  in  respect  to  usefulness, 
appearance,  durability,  and  comfort,  as  compared  with  other  pro- 
cesses and  appliances  in  use. 

Surgical  and  mechanical  operations  of  the  most  delicate  nature 
are  required.  ISTothing,  indeed,  in  dentistry  demands  finer 
manipulation.  A  practical  consideration  of  the  subject  will  show 
that  a  knowledge  of  anatomy,  pathology,  and  therapeutics,  and 

5 


6  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

ae  well  mechanical  and  artistic  skill,  are  necessary  to  tlie  correct 
treatment  of  cases  and  the  proper  performance  of  the  operations 
indicated.  Among  the  principal  steps  in  an  operation  may  be 
named,  first,  the  preparatory  treatment  of  the  natural  roots  and 
teeth  for  the  final  process,  involving  the  diagnosis  of  present  or 
probable  lesions  and  the  prescription  of  whatever  remedial  or 
prophylactic  measures  may  be  needful;  second,  in  crown- work,  the 
adaptation  of  the  artificial  crowns  to  the  cervical  portion  of  the 
natural  roots  and  the  contiguous  membranes,  and  the  restoration 
of  the  articulation  and  the  anatomical  contour;  and,  in  bridge- 
work,  the  selection  of  suitable  teeth  or  roots  for  foundation  piers 
or  abutments,  and  the  choice  and  adaptation  in  constructive  prac- 
tice of  the  forms  which  will  insure  the  highest  degree  of  stability 
and  best  sustain  the  force  of  occlusion,  thereby  avoiding  abnormal 
positions  and  conditions. 

The  practice  of  crown-  and  bridge-work  by  dentists  possessing 
the  requisite  attainments  and  governed  by  correct  ethical  princi- 
])les  gives  results  which  have  gradually  established  its  value,  re- 
moving erroneous  impressions  and  insuring  a  wide  professional 
and  public  indorsement  of  this  important  branch  of  prosthetic 
dentistry.  Its  extraordinary  facilities  for  preserving  and  replac- 
ing teeth  have  made  for  it  the  position  in  dental  art  which  it 
m.erits. 


PART  I. 

PREPARATORY  TREATMENT  OF  TEETH  AND  ROOTS  FOR 

CROWN-WORK. 


PEEPAKATORY  TREATMENT  OF  TEETH  AND  ROOTS 
FOR  CROWN-WORK. 

Prepakatoey  treatment  of  teeth  and  roots  for  crown-work 
includes,  in  addition  to  the  shaping  required  to  fit  them  for  the 
reception  of  the  crowns,  the  bringing  about  of  the  healthiest 
possible  condition  in  the  teeth  and  roots  and  the  adjacent  parts, 
as  the  cure  of  existing  lesions,  the  removal  of  calculus  where 
necessary,  and  the  adoption  of  such  measures  as  shall  prevent  the 
i-ecurrence  of  old  troubles  or  the  inception  of  new. 

Notwithstanding  all  that  advanced  knowledge  of  therapeutical 
agents  and  skill  in  their  use  permit,  there  are  many  teeth  and 
roots  which  cannot  be  rendered  suitable  for  the  successful  applica- 
tion of  crovm-  or  bridge-work.  Roots  which  are  permeated  and 
softened  by  decay,  exposed  or  loosened  from  absorption  of  the 
gums  and  alveoli,  or  affected  with  irremediable  disease  of  the 
investing  membranes,  should  be  thus  classed.  Cases  in  which 
abscess  with  necrosis  has  extensively  impaired  the  walls  of  the 
alveoli  are  equally  intractable. 

Experience  shows  that  the  results  in  this  department  of  den- 
tistry depend  largely  upon  diathesis  or  constitutional  tendency 
and  upon  the  attention  given  to  the  preservation  of  the  health 
of  the  mouth;  and  these  conditions  should  be  carefully  estimated 
in  the  selection  of  a  system  of  treatment  and  the  method  of  its 
application. 


CHAP TEE   L 

THE    PULPS   OF   TEETH— THEIK   PEESEKVATION    OR   DEVITALI- 
ZATION—PULP-CAPPING. 

The  preservation  of  the  vitality  of  the  pulps  of  the  teeth  is  a 
matter  of  as  much  importance  in  connection  with  crovi^n-  and 
bridge- work  as  in  any  other  class  of  operations,  though  the  excision 
of  natural  crowns  for  the  purpose  of  utilizing  the  roots  as  abut- 
ments for  bridge-work  is  extensively  practiced,  and  is  defended 
by  some  on  the  theory  that  the  vitality  of  the  dentin  is  to  some 
extent  maintained  by  the  cementum  after  the  extirpation  of  the 
pulp,  and  by  others  on  the  plea  that  in  a  fully  developed  tooth  the 
pulp,  being  the  formative  organ,  is  of  no  further  value  when  root- 
canal  treatment  is  properly  conducted. 

The  pulp  after  going  through  progressive  changes  which  consti- 
tute its  original  function  assumes  a  fixed  anatomical  character. 
It  becomes  the  source  of  the  vascular  and  nervous  supply,  from 
which  the  dentin  derives  and  maintains  its  vitality.  The  proto- 
plasmic bodies  of  the  pulp  unite  with  the  living  matter  of  the 
tubuli,  which  anastomose  to  a  limited  extent  with  those  of  the 
cementum  through  the  intervening  protoplasmic  bodies  in  the 
interzonal  layer. 

This  distribution  and  relative  connection  of  living  matter  as 
described  refers  to  an  existing  state  of  perfect  vitality  of  all  the 
parts.  When  the  pulp  loses  its  vitality,  an  entirely  different 
condition  results.  The  tubuli  are  then  deprived  of  vital  circula- 
tion, except  along  the  line  of  the  outer  portion  of  the  dentin, 
where,  in  the  interzonal  layer,  the  fibrillse  anastomose  vsdth  the 
living  matter  of  the  cementum.  The  vitality  supported  by  this 
anastomosis  is  almost  entirely  confined  to  this  part,  the  nutrient 
supply  being  insufficient  to  assume  the  functions  of  the  pulp  and 
maintain  circulation  in  the  main  body  of  the  dentin.  (See  Plates 
I,  II,  III.)i 

opiate  I. — Longitudinal  section  of  the  root  of  a  superior  bicuspid,  at  junction 
of  dentin  with  cementuni.  C,  cementum;  D,  dentin;  I,  intei-zonal  layer;  L, 
lacunse  of  cementum.     X  175. 

10 


Platk  I. 


Plate  II. 


Nf'*v,:> 


,:•»»  » 


Plate  III. 


Fk(jm  .Specimens  mai>e  by  M.  H.  Fletcher,  M.  D.,  Dentist.    Cincinnati,  Ohio. 


E.    MOEBfUS,   CAMDEN,    N.    J. 


THE  I'ULFS  OF  TEETH. 


11 


Cliemical  analysis  of  the  dentin  shows  that  the  organic  matter, 
consisting  principally  of  the  fibrillse,  exists  in  the  proportion  of 
nearly  25  per  cent,  to  64  per  cent,  of  lime-salts.^ 

When  the  pulp  has  been  removed,  the  devitalized  fibrillse  still 
remain,  and,  unless  antiseptic  root-canal  treatment  has  been  thor- 
oughly carried  out,  they  are  capable  of  generating  septic  gases 
which  will  exert  an  influence  in  producing  irritation  of  the  cemen- 
tum  and  pericementum.  An  examination  of  the  investing  mem- 
branes of  pulpless  teeth  as  treated  generally  shows  the  existence  of 
a  percentage  of  abnormal  conditions,  by  which  their  firmness  is  to 
some  extent  impaired,  their  susceptibility  to  acute  inflammation  in- 
creased, and  their  reliability  as  foundations  for  crown-  or  bridge- 
work  greatly  lessened  when  compared  with  teeth  which  have  living 
pulps.  Observation  of  gold-capped  pulpless  natural  crowns  of 
teeth  also  has  shown  the  author  that  the  dentin  of  such  teeth  in 
the  course  of  years  gradually  softens  to  such  an  extent  as  to  impair 
their  strength. 

In  cap-crown  work,  facilities  are  afforded  for  the  preservation 
of  pulps  in  the  posterior  teeth.  Thus,  in  a  case  vergiiig  on  ex- 
posure, only  partial  removal  of  the  decay  is  usually  necessary, 
as,  when  the  operation  is  completed,  the  natural  crown  will  be 
hermetically  inclosed  by  the  artificial  one.  In  bridge-work, 
proper  methods  of  practice  in  a  large  percentage  of  cases  will  also 
permit  the  anterior  teeth  to  be  used  as  abutments  without  the 
extirpation  of  their  pulps  or  the  excision  of  their  crowns. 

Extirpation  is  demanded  for  those  pulps  whose  permanent 
preservation  cannot  be  placed  beyond  donbt,  as  failure  involves 

Plate  II. — A  field  taken  from  Plate  I  in  position  marked  A.     L,  lacunae  of 
cementum  ;  C,  canaliculi  of  dentin;  I,  interzonal  layer.     X  210. 

Plate  III. — A  field  taken  from  Plate  I  in  position  marked  B.      L,   L,   L, 
lacunae  of  cementum  ;  I,  interzonal  layer;  D,  dentinal  tubes  and  their  nearest 
approach  to  the  lacunae.     X  210. 

A  study  of  these  plates  demonstrates  the  limited  nature  of  the  anastomosis  of 
the  fibers  of  living  matter  of  the  dentin  and  cementum. 

'  The  analysis  of  dentin  by  Dr.  G.  V.  Black  gives  an  average  of — 

Lime-salts    .         .         .         .         .         .         .         .         .         .         .         .63.54 

Organic  matter     .         .         .         .         .         .         .         .         .         .         .25.36 

Water 11.06 

Age  slightly  lessens'  the  proportion  of  living  matter  and  increases  the  percent- 
age of  lime-salts. 


12  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

more  serious  consequences  in  crown-  and  bridge-work  tlian  in 
filling-operations.  The  lesions  of  the  pulp  which  seem  to  require 
its  extirpation,  according  to  the  generally  expressed  opinion  on 
the  subject,  are  exposure  mth  hypertrophy  or  rupture  of  the  pulp- 
sac,  congestion,  and  pulpitis  which  does  not  yield  promptly  to 
remedial  treatment.  Pulps  actually  exposed  by  decay  are  seldom 
found  in  a  normal  condition  otherwise,  and  they  are  only  rarely 
proper  or  hopeful  subjects  for  remedial  treatment.  Atrophy  of 
the  membrano.  ehoris,  or  investing  membrane,  which  comprises 
the  layer  of  odontoblasts,  usually  exists  at  the  part  exposed,  and, 
as  any  subsequent  calcification  must  depend  on  the  activity  of  the 
odontoblasts,  it  is  evident  that  the  existence  of  the  condition 
referred  to  affords  a  strong  argument  against  the  advisability  of 
capping  pulps  in  cases  of  extensive  or  even  slight  exposure.  The 
difiiculty  of  securing  a  condition  of  asepsis  of  the  exposed  and 
diseased  parts  so  perfect  as  to  assure  them  against  the  invasion 
of  micro-organisms  subsequent  to  capping  is  an  additional  argu- 
ment against  the  operation. 

Pulps  which  are  in  a  normal  condition,  still  protected  by  a 
layer  of  even  decomposed  or  partly  decomposed  dentin,  usually 
admit  of  successful  treatment.  In  such  cases  the  decayed  dentin 
may  be  excavated  from  the  side  walls  of  the  cavity,  but  that  in 
the  region  of  the  pulp  should  be  only  superficially  removed;  in 
some  cases  this  portion  may  be  allowed  to  remain  undisturbed. 

Pulp-Capping. — The  operation  of  capping  a  pulp  should  in- 
clude, as  a  necessary  precaution  against  subsequent  irritation,  the 
thorough  disinfection  of  any  remaining  decomposed  dentin.  An 
excellent  method  of  disinfection  is  to  first  thoroughly  wash  the 
cavity  several  times  with  tepid  water  thrown  gently  from  the 
large  point  of  a  syringe  around  the  sides  of  the  cavity ;  then,  taking 
measures  to  prevent  the  entrance  of  saliva,  wipe  the  cavity  with 
absorbent  cotton  and  pass  over  its  surface  a  light  current  of  hot 
air  from  a  hot-air  syringe.  The  heat  should  be  sufiicient  to  cause 
some  discomfort  to  the  patient,  but  not  enough  to  produce  irrita- 
tion of  the  pulp.  The  dried  cavity  is  then  immediately  saturated 
with  carbolic  acid  previously  warmed-^  to  the  normal  temperature 

1  Thermal  shock  to  the  pulp  is  as  unwarranted  from  the  application  of  cold 
carbolic  acid  as  if  produced  in  any  other  manner. 


THE  I' LLPS  OF  TEETH.  I3 

of  the  body  by  holding  the  pellet  of  cotton  on  which  it  is  applied 
over  the  flame  of  a  lamp  for  a  moment.  The  carbolic  acid  relieves 
any  pain  caused  by  the  evaporation  of  moisture,  and  disinfects 
and  sterilizes  any  decomposed  matter  in  proximity  to  the  pulp. 
The  object  of  the  application  of  the  carbolic  acid  having  been 
accomplished,  the  surplus  may  then  be  removed  from  the  sur- 
face. To  this  end  the  cavity  should  first  be  wiped  with  absorbent 
cotton,  and  hot  air  again  introduced  to  evaporate  the  carbolic  acid 
sufficiently  to  give  a  dry  appearance  to  the  surface.  This  second 
application  of  hot  air,  owing  to  the  effect  of  the  drug,  will  cause 
very  little  or  no  pain. 

This  method,  if  practiced  early  in  the  preparation  of  the  cavity, 
will  be  found  to  considerably  obtund  sensation,  and,  through  the 
dryness  secured,  to  materially  facilitate  the  removal  of  the  decom- 
j)osed  dentin.  A  reasonable  amount  of  the  decayed  portion 
should  be  cut  away,  as  it  lessens  the  difficulty  of  proper  disinfec- 
tion. For  excavating  in  the  region  of  the  pulp-chamber,  spoon- 
shaped  excavators  should  be  used  invariably.  For  the  thorough 
disinfection  of  dentin  and  removal  of  hypersensitive  conditions, 
the  author  practices  the  method  of  previously  placing  and  sealing 
in  the  cavity  for  from  two  days  to  a  week  a  mixture  of  precipitated 
chalk  and  carbolic  acid  and  oil  of  cloves  in  equal  parts.  A  small 
quantity  of  aristol  may  also  be  added.  ^ 

The  disinfected  dentin  over  the  pulp  is  then  varnished  with 
chloro-gutta-percha,  or  some  other  preparation  suitable  for  the 
purpose,  and  capped  with  oxyphosphate  or  oxychlorid,  as  pre- 
ferred. When  the  capping  is  set,  the  remainder  of  the  cavity  is 
filled  with  the  same  cement  as  the  capping,  or  with  amalgam. 

Some  preference  is  given  to  oxychlorid  of  zinc  as  a  pulp- 
capping  over  the  oxyphosphate,  because  of  its  antiseptic  properties ; 
but  its  use  invariably  requires  a  thorough  application  of  chloro- 
gutta-percha  to  thin  areas  of  dentin  over  the  pulp. 

Pulp-capping,  when  necessary,  should  precede  any  other  opera- 
tion, and  no  subsequent  procedure  is  admissible  until  the  success 
of  that  operation  is  assured,  the  time  allowed  for  this  purpose 

'The  chalk  is  placed  in  a  mortar,  and  the  carbolic  acid  and  oil  of  cloves  grad- 
ually introduced  and  thoroughly  incorporated  with  the  chalk  by  trituration  until 
the  mixture  becomes  a  plastic  mass. 


14  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

being  governed  by  the  requirements  of  each  case.  A  non-vital 
condition  of  the  pulp  in  one  root  of  a  tooth  contraindicates  any 
attempt  to  preserve  it  in  any  of  the  other  roots,  in  connection  vs^ith 
crown-  and  bridge-work.  The  rubber-dam,  when  its  use  is  practi- 
cable, will  be  found  a  material  aid  in  difficult  pulp-capping 
operations. 


CHAPTEK   II. 

DEVITALIZATION  OF  THE  PULP. 

In  preparation  for  crown-work  two  methods  of  devitalization 
are  practiced:  the  heroic, — instantaneous  devitalization,  or  extir- 
pation,— and  gradual  devitalization  by  arsenical  treatment. 

Instantaneous  devitalization  can  be  accomplished  by  fii-st  ad- 
ministering to  the  patient  sufficient  nitrous  oxid  to  produce  partial 
anesthesia,  then  with  a  drill  quickly  opening  into  the  pulp- 
chamber,  and  lacerating  the  pulp  well  up  the  canal  with  a  probe 
or  smooth  broach.  Instantly  afterward  a  pellet  of  cotton,  satu- 
rated with  carbolic  acid,  is  forced  up  the  canal,  and,  if  possible,^ 
left  until  the  next  day,  when  the  pulp  will  be  found  in  a  coagu- 
lated mass  that  is  easily  removed  entire. 

Devitalization  of  the  pulp  as  just  described  is  practicable  only 
in  teeth  in  normal  condition.  In  acute  inflammation,  after  lacera- 
tion of  the  pulp,  warm  water  should  be  gently  injected  into  the 
pulp-chamber,  and  sedative  agents  then  applied.  Subsequent 
treatment  should  be  such  as  will  complete  the  devitaKzation  and 
extirpation  of  the  pulp. 

Cataphoresis. — ^In  cases  of  actual  exposure  of  the  pulp  the 
rubber-dam  can  be  applied,  the  exposed  pulp 
obtunded  with  hydrochlorate  of  cocain,  applied  ^^"-  ^• 

in  saturated  solution;  the  diffusion  may  be 
hastened  with  electrolysis.  As  soon  as  the 
action  of  the  cocain  is  manifest,  the  pulp  may 
be  extirpated. 

Excision  of  the  crown  and  instantaneous  ex-  \      \       ^ 
tirpation  of  the  pulp  is  practiced  as  follows: 
Two  parallel  grooves  are  cut  opposite  to  each 
other,  through  the  enamel,  deep  into  the  dentin, 
one  on  the  labial  portion  of  the  tooth  and  the  other  on  the  palatal 
w-all,  close  to  the  gum,  with  a  rapidly  revolving  corundum  or 
rubber  and  corundum  disk  (Fig.  1).     Then  with  excising  forceps,. 

16 


16 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


the  cutting-edges  of  whicli  are  inserted  in  tliese  grooves,  the  crown 
is  qnicklj  severed  from  the  root  (Fig.  2).  The  pnlp  either  adheres 
to  the  excised  crown,  leaving  the  canal  empty,  or  remains  in  the 
root,  fully  exposed.  In  the  latter  case,  a  pointed  piece  of  orange- 
wood,  previously  cut  to  fit  the  canal,  and  saturated  with  carbolic 
acid,  is  quickly  driven  with  a  blow  into  the  pulp  toward  the  apex 
of  the  root  (Fig.  3).  When  the  wood  is  withdrawn,  the  pulp 
usually  adheres  to  it;  if  not,  the  wood  is  instantly  reinserted,  cut 
Fig.  2.  off  and  drilled  out  with  the  pulp,  using  Gates- 

Glidden  drills  in  the  upper  portion  of  the 
canal.  In  this  operation  only  trifling  pain  is 
experienced  by  the  patient,  as  the  pulp  is 
paralyzed  by  shock  in  the  excision  of  the 
crown,  or  by  being  forced  upward  toward  the 
foramen  and  against  the  walls  of  Fig.  3. 

the  canal. 

The  objections  to  this  opera- 
tion are,  that  if  the  pulp  is 
not  successfully  extracted  entire 
with  the  wood  the  canal  be- 
comes filled  with  clotted  blood, 
which  is  difficult  to  remove  from 
the  extreme  end;  also  that  the  U 
root  and  socket  are  jarred  by  the  forceps  in  excising  the  crown; 
but,  expertly  performed,  it  is  advantageous  in  many  cases,  though 
it  should  be  confined  to  cases  where  the  pulps  are  in  normal 
condition. 

In  cases  of  actual  exposure  in  which  excision  of  the  crown 
cannot  be  safely  practiced,  as,  for  instance,  in  a  bicuspid,  a  por- 
tion of  the  walls  and  grinding-surface  may  be  removed  to  the 
line  of  the  root-canal,  the  palp  obtunded  with  carbolic  acid,  and 
the  wood  point  then  forced  up  the  root-canal  in  the  same  manner 
as  in  excising  the  crown. 

Devitalization  with  Arsenious  Acid. — The  methods  of  devital- 
izing previously  described  are  applicable  principally  to  the  pulps 
of  incisors  and  cuspids.  In  the  posterior  teeth,  which  do  not  so 
well  permit  the  heroic  treatment,  recourse  is  had  to  arsenious 
acid,  notwithstanding  the  numerous  objections  to  its  use.  Two 
theories  as  to  the  mode  of  its  action  in  devitalizing  are  widely 


DEVITALIZATION  OF  THE  PULP.  17 

entertained:  First,  that  i1s  toxic  effects  produce  hyperemia,  which 
stops  circulation;  the  other  is  thrombosis.-^ 

This  theory  of  thrombosis  might  account  for  the  gradual  devital- 
ization of  the  pulp  toward  the  foramen. 

Whatever  the  action  of  arsenic  on  the  pulp  may  be,  it  always 
causes  an  infiltration  of  the  tubuli  of  the  dentin  with  certain 
constituents  of  the  blood,  probably  the  liquor  sanguinis.  The 
residue  of  the  infiltration,  after  the  devitalization  of  the  pulp, 
to  some  extent  remains  in  the  tubuli,  and  increases  the  difficulty 
of  producing  an  aseptic  condition  of  the  dentin.  It  is  asserted 
that  in  some  cases  arsenic  affects  the  vitality  of  the  cementum, 
while  after  instantaneous  extirpation  of  the  pulp,  when  arsenic 
is  not  used,  vitality  is  assured. 

Practical  experience  shows  that  usually  instant  devitalization 
or  extirpation  is  the  most  satisfactory  in  general  and  final  results. 
Arsenic,  when  used,  should  be  applied  directly  to  the  pulp  in  the 
smallest  quantity  possible  to  effect  its  devitalization,  and  securely 
sealed  in  the  cavity. 

In  cases  of  non-exposure,  requiring  its  application,  a  small 
opening  into  the  pulp-chamber  should  be  made.  This  can  be 
accomplished  with  but  little  pain  to  the  patient  with  a  very  small, 
sharp,  spear-headed  drill,  rapidly  revolved  by  the  engine.  The 
drill  should  be  held  steadily  under  gentle  pressure  at  one  point  in 
the  line  of  the  intended  exposure,  until  the  pulp  is  slowly  and 
gradually  reached,  and  not  suddenly  punctured  with  the  drill- 
point.  The  drill  should  be  occasionally  removed  and  the  cavity 
flooded  wdth  carbolic  acid  during  the  operation.  Cataphoresis 
may  also  be  practiced. 

The  use  of  arsenic,  combined  with  agents  which  are  non- 
coagulants  of  albumen,  is  recommended  in  preference  to  combin- 
ing it  with  creasote  or  carbolic  acid.  Dr.  Harlan's  method  is  to 
apply  an  anodyne,  such  as  wine  of  opium,  for  a  minute  or  two, 
and  then  the  following  paste : 

R — Arsenious  acid,  gi ; 
Muriate  of  cocain,  ^ii; 
Lanolin  in  quantity  sufficient  to  make  a  stiff  paste. 

The  application  should  be  kept  in  position  no  longer  than  is 

^See  Dr.  L.  C.  Ingersoll's  "Dental  Science,  Questions  and  Answers,"  page  96. 

8 


18  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

necessary  to  effect  the  devitalization  of  the  pulp,  twelve  to  forty- 
eight  hours  being  sufficient  for  the  purpose.  The  pulp  is  then 
punctured,  a  saturated  solution  of  tannin  in  glycerin  applied  and 
securely  sealed  in  the  cavity,  and  the  patient  dismissed  for  several 
days.  At  the  end  of  that  time,  in  favorable  cases,  the  pulp  can  be 
removed  entire.  The  saliva  should  be  entirely  excluded,  the 
rubber-dam  being  applied  when  practical,  and  peroxid  of  hydrogen 
or  absolute  alcohol,  instead  of  water,  used  in  the  treatment.-^ 
When  creasote  or  carbolic  acid  is  used  in  combination  with  arsenic, 
the  same  method  of  subsequent  treatment  may  be  practiced. 
When  the  position  of  the  tooth  or  root  makes  the  application  of 
the  rubber-dam  extremely  difficult  or  impracticable,  the  operation 
can  be  successfully  conducted  without  its  aid  in  this  way:  At 
short  intervals  during  operative  proceduies,  at  each  sitting  of  the 
patient,  thoroughly  syringe  the  pulp-cavity  with  peroxid  of 
hydrogen,  preventing  the  entrance  of  the  saliva  by  at  once  insert- 
ing a  pellet  of  cotton  saturated  with  the  peroxid,  oil  of  cloves,  or 
some  other  antiseptic.  The  tooth  can  then  be  protected  from  the 
saliva  by  any  of  the  usual  methods  practiced,  and  the  treatment 
proceeded  with. 

^  See  Denial  Cosmos,  vol.  xxxiii,  page  138. 


CHAPTEK   III. 


Fig.  4. 


PULPLESS     TEETH— PKEPAKATION     OF      ROOT-CANALS— THEIR 
TREATMENT,  DISINFECTION,    AND   FILLING. 

The  treatment  of  piilpless  teeth  or  roots  consists  in  as  thorough 
s  performance  as  possible  of  the  following  operations: 

First.     Removal  of  the  contents  of  the  canals. 

Second.  Disinfection  of  the  root-canals  and  the  dentin,  and  the 
establishment  of  permanent  aseptic  conditions  by  mummification 
of  the  contents  of  the  tubuli. 

Third.     Closure  of  the  apical  foramen. 

Pre'paration  of  Root-Canals. — A  knowledge  of  the  usual  posi- 
tions of  the  root-canals  in  the  different  teeth  is  essential  for  a  gener- 
ally successful  performance  of  this  operation,  which 
is  greatly  facilitated  by  the  ease  with  which  direct 
access  to  the  root-canals  is  obtained  in  cro^vn-work. 
(See  Plate  IV.)^  In  the  anterior  teeth,  the 
removal  of  the  coronal  section  directly  exposes  the 
pulp-chamber.  In  bicuspids  and  molars,  for  all- 
gold  crowns,  the  leveling  of  the  occluding  surface 
(see  Fig.  4)  and  removal  of  a  portion  of  the  side 
most  involved  by  decay  should  be  preliminary. 
An  opening  is  first  made  into  the  center  of  the 
pulp-chamber  in  a  line  with  the  root-canals  suffi- 
cient to  give  free  and  direct  access  to  them,  and 
any  remaining  portion  of  the  pulp  is  removed  mth 
broaches.  A  few  fibers  of  cotton  twisted  around  the  serrated  por- 
tions of  the  broach  will  admit  of  its  easy  removal  in  case  of 

1  Plate  IV. — Figs.  1  and  2  represent  the  superior  and  inferior  teeth  in  trans- 
verse section  through  the  base  of  the  pulp-chamber  in  the  crown,  showing  the  en- 
trance to  the  root-canals. 

Figs.  3  and  4  represent  the  superior  and  -inferior  teeth  in  transverse  section 
through  the  root-canals  as  they  diverge  from  the  pulp-chamber. 

aa,  hb,  cc,  dd,  ff,  dd,  and  ee,  Figs.  3  and  4,  show  the  relative  shapes,  whether 
circular,  oval,  or  flattened,  of  the  root-canals  in  the  teeth  they  severally  represent. 

19 


Sectional  view  of 
an  inferior  molar 
decayed  on  the  pos- 
terior approximal 
side.  A,  the  line  to 
which  the  crown 
should  be  removed 
to  facilitate  en- 
trance to  the  pulp- 
chamber. 


Plate  IV. 


,^        /f^ 


'%\oy  I 


i  i 


5^ 


""S^e^ 


TREATMENT  OF  PULPLESS  TEETH. 


21 


Fig.  5. 


breakage.  The  canals  arc  tlieii,  guided  by  frequent  explorations 
with  a  fine  probe,  carefidly  enlarged  with  Gates-Glidden  drills 
(Fig.  5).  At  least  three  sizes — large,  medium,  and  small — of 
drills  each  for  the  right-angle  and  the  direct  hand-piece  are  re- 
quired. Very  little,  if  any,  'pressure  should  be  put  upon  them 
when  in  motion,  as  they  will  move  forward  of  themselves.  Under 
pressure  the  formation  of  a  false  passage  in  a 
curved  root  is  possible,  or  the  small  drill  might 
be  broken  off  or  forced  through  the  apical 
foramen  with  disastrous  consequences,  where 
alveolar  abscess  did  not  exist.  ISTeither  should 
drills  be  forced  into  canals  closed  by  calcifica- 
tion, nor  beyond  the  line  of  the  zone  of 
cementum  at  the  end  of  the  root,  nor  through 
a  constriction  which  a  fine,  flexible  probe 
cannot  enter,  nor  around  a  curve  sharp 
enough  to  be  unsafe  to  pass.  A  slight  pain  is 
usually  experienced  when  they  enter  the  zone  of  sensibility  formed 
by  the  cementum  which  composes  the  end  of  the  root,  of  the 
slightest  symptom  of  which  the  patient  should  be  instructed  to 
instantly  inform  the  operator.  The  probe-like  points  of  these 
drills  do  not  cut,  but  simply  guide  the  drills  and  confine  them  to 
the  line  of  the  canal.  They  should  be  gently  given  a  slight  for- 
ward and  backward  motion  in  the  canal,  and  treated  more  as 
reamers  than  drills.  The  occasional  quick  withdrawal  of  the 
drill  from  the  canal  during  the  process  of  drilling  will  aid  removal 
of  the  debris.  The  depth  to  which  a  canal  may  be  enlarged  or 
reamed  is  regulated  by  its  actual  length  and  the  above-mentioned 
conditions,  and  the  diameter  of  the  enlargement  by  the  shape  and 
dimensions  of  the  root.  The  use  of  these  drills  is  condemned  by 
some  for  reasons  attributable  to  their  careless  or  improper  employ- 
ment, but  they  are  indorsed,  in  experienced  hands,  for  their 
adaptability  to  the  work  under  consideration.  They  should  be 
frequently  sharpened  with  a  suitably  shaped  piece  of  Arkansas 
stone.  The  Palmer  root-canal  excavators  also  will  be  found 
serviceable  to  open  up  a  canal  and  enlarge  it  in  accordance  with 
its  original  shape.  Donaldson  pulp-canal  instruments  are  also 
useful  in  the  upper  portion  of  canals  or  in  those  of  very  small 
caliljer.       A   fifty   per   cent,    aqueous   solution    of   sulfuric    acid 


22  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

pumped  into  the  orifices  of  root-canals  with  cotton  wound  on  a 
broach  is  most  effective  as  an  aid  in  opening  up  very  small  canals 
or  those  partly  closed  by  calcification. 

In  the  former  case  the  acid  softens  the  dentin  of  the  sides  of  the 
canal  so  that  the  friction  of  a  smooth  broach  will  materially 
enlarge  it;  in  the  latter,  in  addition  to  this  effect,  it  decomposes 
the  calcified  contents  of  the  canal.  This  enlargement  of  the  canal 
with  the  smooth  broach  will  usually  admit  the  introduction  of  a 
Donaldson  barbed  broach,  by  which  the  canal  can  be  much  more 
rapidly  enlarged.  Canals  by  this  method  can  almost  invariably 
be  safely  opened  and  enlarged  to  the  apex. 

The  moderate  reaming  of  a  root-canal  not  only  simplifies  the 
operation  of  filling,  but  also  opens  up  the  ends  of  the  tubuli  and 
facilitates  the  permeation  of  antiseptic  agents. 

Treatment  and  Disinfection. — Pulpless  teeth  are  presented  for 
treatment  in  one  of  the  four  following  conditions: 

1.  Where  a  healthy  or  non-putrescent  pulp  has  just  been  extir- 
pated from  the  canals. 

2.  Where  on  opening  into  the  pulp-chamber  it  is  found  empty 
and  dry,  with  the  pulp  mummified  or  calcified  in  the  root-canals, 
and  the  root  externally  in  a  healthy  condition. 

3.  Where  the  pulp  is  found  diseased  or  in  a  putrescent  condi- 
tion. 

4.  Where  alveolar  abscess  is  present  and  a  septic  condition  of 
the  canals  and  dentin  exists. 

In  the  first  and  second  classes  the  treatment  should  be  directed 
to  assuring  a  continuance  of  the  existing  aseptic  condition,  and 
as  immediately  as  possible  the  filling  of  the  canal;  in  the  third 
and  f ourtli  classes,  to  bringing  about  an  aseptic  condition  by  dis- 
infection and  sterilization,  and  making  certain  of  its  future  maim 
tenance,  including  incidentally  the  cure  of  any  existing  disease 
of  the  external  membrane  or  of  the  alveolus. 

In  cases  of  the  first  and  second  classes,  if  possible,  saliva  should 
be  excluded  from  the  pulp-chamber  and  canals  during  their  entire 
preparation  and  filling.  If  necessary,  peroxid  of  hydrogen  can 
be  used  instead  of  water.  The  instruments  should  be  sterilized, 
and  the  broaches,  if  serrated,  had  better  be  new.  In  the  third  and 
fourth  classes,  exclusion  of  saliva  or  water  is  not  necessary  in  the 
preliminary  work  on  the  canal;  water  may  be  freely  used  until 


TREATMENT  OF  PULl'LESS  TEETH. 


23 


the  process  of  disinfection  and  sterilization  is  commenced.  Then 
and  thereafter  its  entrance  must  be  prevented.  To  this  end  the 
rubber  dam  should  be  applied  if  practicable.     When  it  is  not,  aai 


Fifi.  6. 


frequently  occurs  with  roots  and  teeth  badly  affected  with  cervical 
decay,  other  means  of  keeping  out  moisture  should  be  resorted  to. 
In  such  cases,  during  each  interruption  in  the  operation  the 
entrance  to  the  canal  should  be  filled  with  absorbent  cotton 
saturated  with  a  suitable  essential  oil  or  antiseptic  fluid,  the  saliva 
being  thus  excluded. 

After  the  canal  has  been  properly  opened  up  and  its  contents 
removed,  it  may  be  washed  out  with  peroxid  of  hydrogen,  and 
wiped  out  with  absorbent  cotton.     The  use  of  sodium  peroxid  is 

Fig.  7. 


recommended  by  Dr.  Kirk  at  this  stage  to  open  up  the  ends  of 
the  tubuli.  The  next  point  in  the  conduct  of  the  operation  is 
to  secure  as  thorough  a  state  of  dryness  in  the  pulp-chamber  by 


24 


ARTIFICIAL  CROWN-  AND  BRIDGE^WORK. 


an  ordinary  (Fig.  6)  or  an  A.  S.  Eiclimond  (Fig.  1)  hot-air  syringe, 
at  a  temperature  higher — as  it  leaves  the  nozzle — than  is  com- 
fortable for  the  finger.  A  root-canal  dryer,  with  the  end  tapered 
as  fine  as  a  broach  at  the  point,  is  then  introduced  into  the  canal. 
The  writer  prefers  the  form  in  which  the  point  is  made  of  silver 
and  the  bulb  portion  of  copper  (Fig.  8).  As  silver  possesses 
remarkable  properties  as  a  thermal  conductor,  the  heat  is  trans- 
mitted to  the  point  of  the  probe  very  rapidly.  The  probe  being 
inserted  as  far  as  possible  up  the  canal  (Fig.  9),  the  patient  is 
directed  to  raise  the  hand  as  a  signal  should  the  heat  cause  pain, 
when  the  probe  must  be  moved  up  and  down  or  withdrawn 
Fig.  8.  ^^^  ^  moment.  This  procedure,  follow-  Fig.  9. 
ing  the  previous  application  of  the  hot 
air  with  the  syringe,  evaporates  the 
moisture  and  aids  the  escape  of  any  i 
gases  present  in  the  root-canals  and  the 
open  ends  of  the  tubuli.  The  point  of 
the  root-canal  dryer  acts  as  a  sterilizer, 
and  may  be  applied  so  hot  as  to  car- 
bonize any  organic  matter  which  it 
reaches  in  the  end  of  the  canal,  and  a 
portion  of  this  can  be  removed  each 
time  on  its  point.  As  the  silver  point 
can  be  tapered  as  small  as  the  finest 
broach,  canal-contents  impossible  to  re- 
move may  be  reached  or  rendered  inert. 
In  cases  of  the  third  or  fourth  class, 
sepsis  being  present,  the  heat  is  very 
serviceable,  as  it  aids  the  escape  of 
gases  from  the  canal  and  dentin  and  acts  as  a  germicide.  When 
in  this  dry  and  heated  condition,  the  dentin  is  in  the  best  possible 
state  for  the  application  of  antiseptic  agents. 

Antiseptic  Treatment. — The  suitability  of  various  antiseptics  to 
the  needs  in  treating  tooth-structure,  their  effectiveness  and  per- 
manency when  so  used,  singly  or  in  combination,  are  subjects 
on  which  great  diversity  of  opinion  exists,  and  which  have  of  late 
been  made  the  object  of  clinical  study  and  scientific  investigation 
and  discussion.  Many  antiseptics  in  common  use  being  coagulantg 
of  albumen  obstruct  the  dentinal  tubuli,  and  consequently  limit 


TREATMENT  OF  Pl'LI'LESS   TEETH.  25 

or  retard  diffusibililj  tliroiigliout  the  dentin.  'J'liis  is  tlie  oljjoc- 
tion  to  the  use  of  carbolic  acid,  creasote,  and  like  agents,  addi- 
tionally to  which  may  he  named  their  inefficiency  to  accomplish 
in  certain  conditions  the  end  sought,  and  as  well  their  eventual 
al)Sorption  from  the  dentin.  Recent  in^'estigations  seem  to  give 
preference  to  such  antiseptics  as  are  nou-coagulative  in  their 
action.  Of  this  character  are  the  essential  oils,  many  of  which 
according  to  Miller,  Harlan,  and  others,  possess  antiseptic  power 
much  greater  than  has  been  commonly  attributed  to  them. 
Acidulated  solutions  of  bichlorid  of  mercury,  peroxid  of  hydrogen, 
sodium  peroxid,  especially  in  preliminary  treatment,  and  various 
preparations  of  iodin,  which  exert  chemical  action  and  retain  their 
antiseptic  properties  for  a  great  length  of  time. 

The  selection  of  antiseptic  agents  is  important,  and  is  indicated 
by  the  conditions  presented  in  a  pulpless  tooth.  Cases  in  which 
a  healthy  pulp  has  just  been  extracted,  or  the  canal  is  aseptic,  are 
different  from  those  with  sepsis  of  dentin  or  diseased  or  putrescent 
pulps.  In  the  first-mentioned  condition,  with  or  without  antisep- 
tic treatment,  favorable  results  usually  follow  root-filling,  the 
advantage  of  a  reliable  antiseptic  agent  in  the  canal  being  only  to 
better  insure  the  continuance  of  a  state  of  asepsis.  In  the  second 
condition  the  state  of  the  dentin,  and  consequently  the  treatment 
to  be  effected,  are  entirely  different.  We  need  the  intervention 
of  agents  that  will  not  only  destroy  ptomaines,  but  exert  a  chemi- 
cal action  on  sulfuretted  hydrogen  and  ethereal  ammoniacal  gases, 
the  products  of  putrefaction,  and  entirely  eliminate  them.  On 
this  depends  the  successful  treatment  of  such  cases,  as  the  pressure 
and  expansion  of  these  gases  are  a  certain  cause  for  constant  peri- 
dental inflammation,  and  so  long  as  they  are  present  in  the 
slightest  degree  in  a  canal  it  is  in  an  unsuitable  condition  to  bo 
closed.  Carbolic  acid,  creasote,  or  the  essential  oils,  in  such  a 
condition  exert  no  chemical  action  on  these  gases,  merely  disguis- 
ing their  odor,  though  by  repeated  dressings  of  cotton  saturated 
with  one  of  these  agents  the  gases  are  absorbed  by  the  cotton,  and 
to  an  extent  slowly  eliminated.  What  is  required  is  the  action  of 
agents  whose  elements  possess  an  affinity  for  the  gases,  and  so 
will  immediately  decompose  them,  forming  new  combinations  and 
entirely  changing  their  character. 

In  accordance  with  these  principles,  the  use  of  iodin  is  indi- 


26  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

cated  and  preference  is  given  to  its  use  in,  practice  to  that  of  the 
other  agents  mentioned.  Its  effects  are  best  obtained  from  some 
one  of  the  preparations  now  in  nse, — aristol,  for  instance,  wliose 
odor  is  entirely  unobjectionable,  in  a  strong  solution  in  one  of 
the  essential  oils.  In  the  writer's  practice  he  favors  the  oils  of 
cloves,  cassia,  and  eucalyptus,  considering  the  oil  of  cloves  more 
sedative  in  action  than  the  others.  He  makes  it  a  point  to  flood 
the  canal  with  the  solution,  thereby  to  some  extent  saturating  the 
heated  dried  dentin  as  well  as  the  cementum  at  the  apex.  A 
more  effective  saturation  can  be  accomplished  by  again  drying  and 
heating  the  dentin  and  applying  the  solution,  or  by  filling  the 
canal  with  cotton  saturated  with  the  solution,  hermetically  inclos- 
ing it  and  letting  it  so  remain  for  a  day  or  two. 

Coagulants,  such  as  creasote  or  carbolic  acid,  are  not  entirely 
non-diffusible  in  devitalized  dentin  or  cementum,  as  decomposi- 
tion or  putrefaction  effects  elementary  changes  in  the  contents  of 
the  tubuli,  but  their  action  is  slow  and  limited  compared  with  that 
of  the  essential  oils.  They  have  also  the  objectionable  feature  of 
being  irritants,  and  unsuitable  where  acute  or  chronic  inflamma- 
tion of  the  peridental  membranes  is  present.  When  a  healthy 
pulp  has  just  been  extirpated,  and  immediate  root-filling  is  prac- 
ticed, the  use  of  carbolic  acid,  creasote,  or  solution  of  chlorid  of 
zinc  is  best  indicated,  the  condition  then  presented  being  entirely 
different  from  that  where  the  pulp  is  diseased  or  putrescent,  or  the 
canal  is  in  a  septic  state.  When  a  healthy  pulp  has  been  re- 
moved, its  minute  fibrous  connections  with  the  walls  of  the  canal 
and  the  vessels  at  the  apical  foramen  are  severed,  and  the  action  of 
an  escharotic  antiseptic  agent,  such  as  carbolic  acid,  is  in  fact  then 
indicated,  as  it  acts  as  a  coagulant  and  instantly  seals  up  the  ends 
of  the  tubuli.  If  immediate  root-filling  is  not  to  be  practiced, 
then  the  prescription  of  such  agents  as  the  essential  oils,  with 
aristol  or  iodoform,  seems  more  suitable,  as  by  their  action  a  sort 
of  mummJfication  of  the  non-vital  organic  matter  follows.  More- 
over, the  oils  possess  advantages  over  the  coagulants  mentioned  as 
they  are  not  miscible  in  water,  and  are  easily  eliminated.  Their 
use  consequently  will  better  tend  to  perpetuate  an  antiseptic  condi- 
tion. 

The  disadvantage  of  immediate  root-filling  is  that,  should  some 
fragment  of  the  pulp  remain  in  the  extremity  of  the  canal,  it  fails 


TREATMENT  OE  EEL  PI. ESS  TEETH.  27 

to  receive  the  benefit  accruing  from  the  reapplication  of  antisep- 
tics, which  would  better  assure  inertness  by  mummification. 

There  is  such  a  thing  as  over-treatment, — an  unnecessarily 
frequent  renewal  of  antiseptic  dressing  in  root-canals,  thereby 
aggravating  or  producing  irritation  of  the  pericementum  at  the 
apex  of  the  root.  Such  cases  may  be  relieved  by  washing  out 
the  canal  with  alcohol  and  applying  the  alcohol  on  the  dressing, 
instead  of  the  agents  previously  employed. 

The  dressing  of  root-canals  is  best  performed  with  the  aid  of 
the  ordinary  smooth,  flexible  rectangular  broaches;  also  root-canal 
dressers,  such  as  the  How.  The  form  of  these  instruments  permits 
fibers  of  cotton  to  be  easily  wound  around  them  lengthwise  and 
over  the  point  in  one  connected  mass.  ^Vhen  the  cotton  is  intro- 
duced in  the  canal,  it  is  retained  on  and  carried  forward  by  the  in- 
strument, which,  when  withdrawn,  leaves  the  cotton  in  position  in 
the  canal  in  the  form  of  a  cone  or  tampon  that  will  favor  the  escape 
of  gases,  and  it  may  still  be  easily  removed  at  any  time.  After 
one  or  more  treatments  in  the  manner  described,  between  which, 
if  interspersed  by  intervals  of  time,  the  antiseptic  agents  must  be 
hermetically  sealed  in  the  cavity  with  gutta-percha,  the  canal  is 
dried  and  the  foramen  closed. 

Closure  of  the  Apical  Foramen  and  Filling  of  the  Canal. — The 
object  of  root-canal  filling  is  to  prevent  the  entrance  of  the  fluids 
through  the  foramen,  and  to  avert,  in  case  of  the  formation  of 
gases,  irritation  of  the  peridental  membranes  by  their  pressure 
or  presence.  Gutta-percha  and  oxychlorid  of  zinc  are  generally 
accepted  as  most  suitable  for  the  purpose.  Either  gutta-percha 
in  the  form  of  chloro-gutta-percha,  or  the  oxychlorid  of  zinc 
mixed  thin,  can  be  pumped  or  placed  in  the  extreme  end  of  the 
canal  with  the  aid  of  a  broach  or  fine-pointed  probe.  This  is 
one  of  the  advantages  that  commend  the  use  of  these  materials. 
When  the  chloro-gutta-percha  has  been  pla<jed  in  the  apex,  the 
remainder  of  the  canal  can  be  filled  with  the  prepared  cones  of 
solid  gutta-percha  until  no  more  can  be  inserted.  A  current  of 
hot  air  should  then  be  thrown  on  the  protruding  ends  of  the 
cones  at  a  temperature  sufiicient  to  soften  them  and  Avarm  the 
dentin,  when  they  should  be  gently  pressed,  but  not  suddenly 
pushed,  up  in  the  canal.  A  slight  twinge  of  pain  to  the  patient 
will  usually  be  the  signal  of  their  complete  impactment  in  the 


28  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

canal.  The  solid  gutta-percha  absorbs  what  little  chloroform  was 
present  in  the  chloro-giitta-percha,  and  the  heat  also  aids  its 
evaporation,  so  that  the  shrinkage  so  often  urged  as  an  objection 
against  the  use  of  chloro-gutta-percha  is  reduced  to  a  minimum. 

An  advantage  possessed  by  oxychlorid  of  zinc  over  other 
materials  is  its  antiseptic  qualities;  its  disadvantage,  the  difficulty 
attending  its  removal  from  the  extremity  of  the  canal  should 
supervening  conditions  require  it.  For  this  reason  the  apex  and 
extremity  of  the  canal  may  be  filled  mth  gutta-percha,  and  then 
the  orifice  and  pulp-chamber  with  oxychlorid.  Wood  and  metal 
shaped  to  fit  the  canal  are  also  much  used  to  fill  root-canals,  but 
unless  a  small  quantity  of  chloro-gutta-percha  or  oxychlorid  of  zinc 
is  placed  in  the  extremity  or  on  the  point  used,  the  entire  closure 
of  the  canal  is  doubtful.  The  use  of  cotton  as  a  filling  in  root- 
canals  is  to  be  condemned,  unless  it  is  sterilized^  or  iodoformized 
and  saturated  with  chloro-gutta-percha  or  oxychlorid  of  zinc  pre- 
vious to  insertion.  Asbestos  is  given  preference  to  cotton  by 
some.  Tin  or  gold  foil  is  difficult  to  insert  without  vacuoles. 
Paraffin  in  combination  with  a  small  quantity  of  aristol,  as  a 
material  to  fill  root-canals,  has  been  suggested  by  Dr.  Kirk,  espe- 
cially after  the  use  of  sodium  peroxid;  sodium  peroxid  being  a 
most  active  solvent  of  albuminous  matter,  in  a  measure  frees  the 
ends  of  the  tubuli  or  a  canal  of  their  organic  contents,  a  condition 
favorable  for  the  use  of  paraffin.  Paraffin  is  aseptic  and  melts  at 
a  low  temperature,  and  mth  a  heated  root-canal  dryer  can  be 
flowed  into  the  ends  of  the  tubuli  or  into  a  minute  canal  not  con- 
sidered safe  to  open  up.  Balsamo  del  Deserto  can  be  used  in  the 
same  manner.  Dr.  Delos  Palmer's  method  of  using  this  prepara- 
tion is  to  carry  a  small  quantity  into  the  cavity  upon  the  point  and 
sides  of  a  broach  connected  with  a  small  metallic  bulb,  which  can 
be  heated  by  electricity  at  the  will  of  the  operator  to  melt  the 
Balsam-O,  and  thus  secure  its  proper  diffusion. 

Ordinary  gutta-percha  should  be  used  to  close  a  foramen  when 
an  abscess  has  just  been  treated  by  injecting  through  it.  The 
length  of  the  canal  should  be  measured  with  a  probe,  and  gauged 

^  Cotton  or  wood  points  may  be  sterilized  \)j  immersing  them  for  a  time  in  a  so- 
lution of  bichlorid  of  mercury  or  a  saturated  solution  of  iodoform  in  ether,  and 
then  drying.  The  prepared  points  should  he  kept  in  a  tightly-corked  bottle. 
When  this  plan  is  followed,  the  odor  of  iodoform  is  avoided  in  the  operating-room. 


TREATMENT  OF  J'ULPLESS  TEETH.  29 

Avitli  a  small  perforated  disk  of  rubber  dam  slippe*!  upon  the 
instrument.  The  gutta-percha  should  then  be  carried  to  position 
on  the  point,  allowance  being  made  for  the  displacement  of  the 
instrument.  As  oil  of  eucalyptus  is  a  solvent  of  gutta-percha,  the 
application  of  this  oil,  alone  or  in  combination  with  iodoform  or 
aristol,  is  recommended  in  the  final  treatment  when  chloro-gutta- 
percha  is  not  used,  as  better  adhesion  of  the  gutta-percha  to  the 
walls  of  the  canal  is  thus  obtained. 

Ample  room  should  be  left  in  imy  root-canal  which  is  to  receive 
the  post  of  a  crown,  as  any  part  of  the  canal  not  occupied  by  the 
post  will  be  filled  by  the  retaining  material. 

A  pulpless  tooth  presented  for  crowning,  the  roots  of  which 
have  been  treated  and  filled  in  some  previous  operation,  should 
be  carefully  examined,  and  if  any  doubt  is  entertained  as  to  its 
hygienic  condition  it  should  receive  the  antiseptic  treatment  above 
described,  as  the  ultimate  success  of  crown-work  depends  largely 
upon  the  thoroughness  of  these  preliminary  operations. 


CHAPTERIV. 

CHKONIC  ALVEOLAR  ABSCESS. 

Majsty  teeth  and  roots  presented  for  crown-work  are  aifected 
with  chronic  alveolar  abscess.  A  general  description  of  an  effec- 
tive method  of  treatment  is  therefore  properly  associated  with  a 
discussion  of  the  subject. 

The  cause  of  chronic  alveolar  abscess  will  be  found  in  a  con- 
tinuation of  those  conditions  which  originally  produced  the  acute 
form.  The  tooth  or  root  being  pulpless,  septic  gases,  generated 
by  the  decomposition  of  organic  matter  in  the  root-canal  and  in 
the  tubuli  of  the  dentin,  find  an  outlet  through  the  open  foramen 
into  the  apical  space,  causing  pericementitis  and  formation  of  pus. 
The  general  treatment  consists  in  the  removal  of  all  septic  matter 
and  gases  from  the  root-canal  and  dentinal  tubuli,  the  destruction 
of  the  pus-sac,  the  application  of  suitable  therapeutic  agents,  and 
the  adoption  of  measures  to  prevent  further  formation  of  pus. 

Chronic  alveolar  abscess  is  usually  found  in  the  following 
forms:  First,  abscess  with  a  fistulous  opening  in  the  gum,  and 
accessible  through  the  root-canal  and  foramen  of  the  root. 
Second,  abscess  with  fistulous  opening,  but  not  accessible  through 
the  apical  foramen.  Third,  abscess  from  which  pus  discharges 
through  the  apical  foramen  and  root-canal,  with  no  opening 
through  the  gum. 

In  the  treatment  of  abscess  of  the  first  form,  the  canal  should 
be  enlarged  as  described  in  the  treatment  of  pulpless  teeth,  and 
the  foramen  opened,  if  possible,  with  a  smooth  broach  without 
the  use  of  a  drill.  Aromatic  sulfuric  acid,  on  cotton,  placed  in 
the  end  of  the  canal  for  a  day,  will  usually  open  up  the  finest 
foramen.  A  small  quantity  of  fifty  per  cent,  aqueous  solution  of 
sulfuric  acid  pumped  into  the  extremity  of  the  canal  with  cotton 
on  the  end  of  a  broach  will  often  enable  a  broach  to  instantly  effect 
a  passage.  Tepid  water  is  then  forced  through  the  foramen  with 
a  fine-pointed  sj^ringe  (Fig.  10)  introduced  well  up  the  canal,  and 
30 


CHRONIC  ALVEOLAR  ABSCESS. 


31 


packed  in  with  gutta-percha;  or  it  may  be  pumped  up  with  cotton 
on  a  broach  until  it  passes  into  the  abscess  and  out  through  the 
fistula.  Peroxid  of  hydrogen  is  next  used  in  the  same  manner. 
Aromatic  sulfuric  acid  may  also  be  injected  through  the  fistulous 
opening  into  the  abscess. 

In  abscesses  of  the  second  form,  where  it  is  impracticable  to 
treat  through  the  foramen,  the  canal  should  be  thoroughly  disin- 
fected, and  a  direct  opening  into  the  abscess  effected  by  the  track 
of  the  fistula,  enlarging  it  if  necessary.  The  abscess  should  then 
be  thoroughly  injected  with  peroxid  of  hydrogen,  and  afterward 
Avith  aromatic  sulfuric  acid,  by  introducing  the  fine  point  of  a 
syringe  into  its  deepest  parts.  The  fistula  must  be  kept  open  while 
treatment  is  conducted  by  inserting  Fig.  10. 

in  it,  at  each  injection,  a  strand  of 
twisted  cotton  saturated  with  oil  of 
cloves,  the  patient  being  directed  to 
remove  it  in  a  few  hours,  or  the  next 
day,  for  which  purpose  the  end  should 
be  left  protruding.  When  the  apical 
foramen  is  open,  one  injection  is 
usually  sufiicient  to  cure  an  abscess; 
but  when  the  foramen  is  closed  and 
the  abscess  is  treated  through  the 
gum,  several  injections  are  sometimes 
necessary. 

In  case  of  "blind  abscess,"  the 
third  form,  first  clean  and  disinfect 
the  root-canal,  then  at  intervals  inject 
the  abscess  through  the  foramen  with  peroxid  of  hydrogen  until 
the  formation  of  pus  ceases,  placing  cotton  saturated  with  oil  of 
cloves  loosely  in  the  canal  sealed  with  gutta-percha.  Should  this 
treatment  fail,  an  opening  through  the  gum  into  the  abscess  must 
be  obtained,  with  a  lance  and  drill,  and  the  same  course  pursued 
as  in  the  first  form  of  abscess. 

An  entrance  into  the  apical  space  can  be  made  almost  pain- 
lessly in  the  following  manner,  as  described  by  Dr.  G.  Y.  Black '.-^ 
"The  mucous  membrane  is  first  dried  at  the  point  at  which  it  is 


1  "American  Sj'stem  of  Dentistry,"  vol.  i,  page  928. 


32  ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 

desired  to  make  the  opening,  and.  napkins  are  so  placed,  as  to 
keep  it  dry.  Then  a  plugging-instrument  with  fairly  sharp 
serrations  and  of  convenient  shape  is  selected.  The  point  of  this 
is  dipped  into  a  ninety-iive  per  cent,  solution  of  carbolic  acid,  and  a 
drop  conveyed  to  the  mucous  membrane;  this  will  at  once  produce 
a  white  eschar.  Then  a  slight  scratching  motion  with  the  serrated 
point  is  begun,  with  a  view  of  removing  the  tissue  that  is  whitened. 
This  IS  continued  until  the  carbolic  acid  is  thick  with  the  debris 
of  the  tissue  torn  up,  then  it  is  dried  out  and  another  drop  added, 
as  before,  and  the  process  continued.  This  is  repeated  as  often  as 
may  be  necessary,  going  deeper  and  deeper  into  the  tissue  in  the 
desired  direction  until  the  bone  is  laid  bare.  Then  a  fresh  drop 
of  the  acid  is  placed  on  the  bone,  and  the  periosteum  carefully 
raised  over  a  sufficient  space;  then  with  a  sharp  chisel  cut  through 
to  the  peridental  membrane.  This  will  generally  cause  some 
pain  and  some  bleeding,  but  after  giving  a  little  time  for  this  to 
cease,  and  adding  more  of  the  acid,  the  apical  space  can  usually 
be  reached  without  difficulty,  l^o  blood  should  be  drawn  at  any 
time  during  the  operation,  except  in  penetrating  the  wall  of  the 
alveolus.  In  doing  this  no  tissue  is  removed  until  it  is  anesthe- 
tized by  the  carbolic  acid.  This  is  a  little  tedious,  but  it  is  almost 
painless,  and  the  general  effect  is  usually  better  than  by  other 
modes  of  penetrating  the  apical  space.  The  carbolic  acid  has  the 
effect  of  modifying  the  pain,  and  the  opening  left  does  not  close 
so  readily." 

A  period  of  entire  cessation  of  discharge  of  pus  is  to  be  con- 
sidered the  most  favorable  indication  of  successful  treatment. 

Thorough  disinfection  and  sterilization  of  the  dentin  and  root- 
canals  are  included  in  the  preliminary  treatment  of  alveolar 
abscess.  As  soon  as  the  treatment  is  followed  by  favorable  indi- 
cations, the  foramen  should  be  closed,  any  further  treatment 
considered  necessary  being  conducted  externally  through  the 
fistula.  This  may  be  facilitated  by  enlarging  the  orifice  with 
tents  of  cotton  saturated  with  oil  of  cloves.  Enlargement  of 
the  fistula  tends  to  encourage  the  process  of  granulation  in  the 
region  which  has  been  occupied  by  the  abscess. 

After  the  abscess  has  been  cured,  the  root-canals  are  filled  as 
described  on  page  27. 

Aromatic  sulfuric  acid  is  a  powerful  astringent  and  germicide. 


CHRONIC  ALVEOLAR  ABSCESS.  33 

It  Avill  be  found  most  useful  in  cases  where  a  slightly  necrosed 
state  of  the  wall  of  the  alveolus  exists.  Its  use  should,  however, 
be  limited,  and  in  subsequent  external  treatment  through  the 
fistula  some  of  the  other  therapeutic  agents  should  be  employed, 
as  the  peroxid  of  hydrogen,  sublimate  solution  (  yt/utt  )j  ^^  the 
essential  oils  or  carbolic  acid,  alone  or  combined  with  one  of  the 
preparations  of  iodin.^ 

Injections  of  sulfuric  acid  in  the  region  of  the  mental  foramen 
should  be  made  cautiously,  and  it  should  not  be  applied  to  an 
abscess  bordering  on  the  antrum  until  the  operator  is  positively 
assured  that  the  abscess  does  not  open  into  that  cavity. 

Amputation  of  tlie  Apex  of  a  Root. — In  long-neglected  alveolar 
abscess,  the  pus-cavity  occasionally  involves  the  alveolus  in  such 
a  way  as  to  destroy  a  considerable  portion  of  the  pericementum 
of  the  end  of  the  root.     The  cementum  of  that        yiq.  11. 
part  is  consequently  devitalized,  and  the  portion 
of  the  root  affected  becomes  degenerated  in  struc- 
ture,  and  saturated  with   septic   matter.     In  this 
condition  it   acquires   the   character   of   a   foreign 
substance,  proves  a  constant  source  of  irritation, 
and  defies  all  efforts  of  the  membranes  to  perfectly 
inclose  or  encj'^st  it. 

In  such  cases,  amputation  of  the  portion  of  the 
root  which  is  denuded  of  pericementum  is  the 
best  course  to  pursue.  An  opening  is  made  in 
the  soft  tissues  over  the  affected  part  in  the  manner 
described  on  page  32,  and  gradually  enlarged  with  a  tent  of  lint 
or  cotton  until  the  diseased  territory  is  fully  exposed  (Fig.  11), 
when  the  devitalized  end  of  the  root  and  any  necrosed  bone  in 
the  territory  are  removed,  and  the  end  of  the  root  smoothed.  The 
canal  should  be  filled  solidly  with  gutta-percha  or  oxychlorid  of 
zinc  previous  to  the  amputation,  so  that  when  the  end  of  the  root 
is  excised  the  stump  will  be  left  smoothly  and  snugly  filled. 
Cocain  can  be  used  in  this  operation. 

The  orifice  of  the  cavity  in  the  gum  should  be  kept  open  and 

1  For  an  extended  consideration  of  this  suly'ect  the  reader  is  referred  to  Dr. 
J.  N.  Farrar's  articles  on  "Sulphuric  Acid  v.  Creasote  in  Treatment  of  Alveolar 
Abscess,"  commencing  in  Dental  Cosmos^  vol.  xx,  No.  7,  and  Dr.  G.  V.  Black's 
article  in  the  "American  Sj^stem  of  Dentistry,"  vol.  i,  page  929. 

4 


34  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

daily  injected  with  a  mild  antiseptic  solution  by  the  dentist  or 
patient  "until  the  cavity  is  filled  by  granulation.  In  cases  where 
extensive  necrosis  of  the  alveolar  process  has  existed,  in  addition 
to  the  daily  injection  the  cavity  should  be  packed  with  a  suitable 
antiseptic  dressing.  Balsam  Peru  has  been  found  by  the  author 
to  be  a  suitable  agent  for  the  purpose,  as  it  assists  the  process  of 
granulation.  When  the  healing  process  is  completed,  crown-work 
can  be  proceeded  with. 

The  amputation  of  roots  requires  skill  and  experience,  and  had 
better  be  confined  to  the  front  teeth  or  those  with  a  single  root, 
excej)t  in  the  hands  of  experts. 


CHAPTEE    V. 


SHAPING  TEETH  AND  ROOTS  FOR  CROWN-WORK. 


The  principles  governing  the  process  of  shaping  the  surface  of 
a  natural  crown  or  root  for  any  style  of  artificial  crown  with  a 
collar  attachment  require  that  the  cervical  portion  of  the  natural 
crown  and  root  shall  he  given  a  form  that  has  longitudinally 
parallel  sides  gauged  to  the  line  of  the  periphery  of  that  part,  and 
that  any  of  the  coronal  section  present  below  it  shall  be  reduced 
at  least  sufficiently  in  size  to  come  within  this  line.  Such  a  form 
is  necessary  to  admit  of  a  perfect  adaptation  of  the  collar. 

The  coronal  section  of  a  natural  crown  to  be  prepared  is  usually 
first  ground  on  the  occluding  surface  with  as  large  a  corundum- 
wheel  as  the  case  will  conveniently  admit  (Fig.  12).     Molars  and 

Fig.  12. 


bicuspids  for  all-gold  crowns  should  have  enough  substance  re- 
moved to  make  a  small  space  between  them  and  the  antagonizing 
teeth.  The  approximal  sides  of  the  cervix  should  be  reduced 
sufficiently  to  allow  a  free  space  between  the  gold  collar  when 
adjusted  and  the  cervices  of  approximal  natural  teeth  or  artificial 
crowns,  to  make  room  for  the  gum  septa.  The  approximal  sur- 
faces are  removed  straight  from  the  cervical  border  to  the  occlud- 
ing surface,  using  corundum  or  rubber  and  corundum  disks 
(Pig.  13)  and  files,  and  last  of  all,  as  injury  to  the  approximal 
teeth  is  then  more  easily  avoided,  the  labial  and  palatal  portions, 
for  which  small  corundum-points  (Fig.  14)  and  wheels  are  best 
adapted.     The  corners  are  then  rounded.     The  cervical  portion, 

35 


36 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


which  includes  the  junction  of  the  dentin  and  enamel,  is  trimmed 
so  that  the  sides  as  illustrated  at  A,  Eig.  15,  are  level  and  parallel 
with  the  line  of  the  root,  and  as  deep  as  the  collar  is  to  be  placed 
(Fig.  16).  For  this  work  small  corundunl-points,  trimmers,  and 
files  can  be  used.  Fig.  17  illustrates  a  trimmer,  made  in  three 
sizes,  which  in  the  ordinary  hand-piece  or  in  the  right-angle  attach- 


FiG.  13. 


Tig.  14. 


ment  will  easily  and  quickly  accomplish  this.  Fig.  18  illustrates 
another  style,  in  the  form  of  a  triangular  pyramid,  which  can  be 
used  as  a  scraper  in  a  hand-socket,  bracing  the  hand  by  resting  the 
thumb  on  the  adjoining  teeth.  The  points  should  be  tempered 
very  hard.  Files  shaped  as  shown  in  Fig.  19  are  useful  in  round- 
portions.     A  smooth  surface  should  be  given  the 


ing  angular 
Fig.  15. 


Fig.  16. 


Fig.   17.        Fig.   18. 
I     4 


Fig.  19. 


cervix.  On  approximal  sides  and  the  curves  to  the  other  sides, 
medium  coarse  corundum  tape  and  wheels  can  be  used  for  this 
purpose. 

In  pulpless  teeth,  the  use  of  excising  forceps  should  be  avoided 
unless  the  parts  admit  of  it  without  serious  shock  to  the  root. 
The  best  plan  is  to  make  a  "succession  of  holes  with  a  spear-shaped 


SHAPING  TEETH  AND  ROOTS  FOR  CROWN-WORK. 


37 


drill  across  the  portion  to  be  removed,  and  then  cnt  between  the 
holes  with  a  fissnre-bur  or  cornndum-disk,  whieh  will  permit  of 
easy  removal  of  the  part  (Fig.  20). 

In  preparing  incisors  and  cuspids  for  gold  collar  crowns  with 
porcelain  fronts,  where  the  pulp  is  to  Ije  ]jreserved,  the  labial 
surface  and  incisive  edge  should  be  ground  down  as  much  as 
possible  without  exposing  the  pulp  or  subjecting  it  to  irritation; 
the  palatal  portion  at  an  angle  from  the  cervical  border  to  the 
incisive  edge,  enough  to  level  its  prominences  of  contour  and  form 
a  slight  space  between  it  and  the  antagonizing  teeth  (Fig.  21). 
Pulpless  incisors  and  cuspids  should  be  prepared  by  grinding  the 
labial  face  to  the  gum^margin,  Avith  the  palatal  portion  slightly 
projecting  and  squared  off  to  the  inner  line  of  the  root-canal. 
(See  Fig.  22.)  Bicuspids  which  are  to  have  porcelain  fronts  are 
given  the  same  general  form  (Fig.  23). 
Fig.  20.     Ftg.  21.        Fig.  22.  Fig.  23.  Fig.  24.  Fig.  25. 


Bicuspids  and  molars  with  or  without  pulps,  for  all-gold  crowns, 
should  have  as  much  of  the  natural  crown  left  as  possible,  as  it 
affords  a  more  secure  and  more  convenient  attachment  for  the 
artificial  crown  than  any  other  method  (Figs.  24  and  25). 

It  should  be  borne  in  mind,  however,  that  unnecessarily  cut- 
ting away  the  enamel  and  dentin  of  teeth  ^^dth  living  pulps  leaves 
them  in  an  extremely  sensitive  condition,  and  is  likely  to  result 
subsequently  in  some  serious  lesion  of  the  pulp.  Slight  sensitive- 
ness, such  as  may  be  readily  caused  in  excessive  shaping,  is  relieved 
by  drying  the  exposed  dentin  with  hot  air  and  applying  carbolic 
acid  two  or  three  times  as  required. 

For  the  porcelain  system,  roots  are  usually  ground  level  with  the 
margin  of  the  gum.     The  palatal  portion  in  some  cases  is  left  a 


88 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


trifle  above  the  margin,  and  the  labial  aspect  should  be  below, 
especially  on  the  front  teeth,  if  it  is  desirable  to  conceal  the  joint. 
The  root-canal  is  shaped  to  the  form  of  the  post  or  pin  to  fit  it 
tightly.  (See  the  articles  on  Gates-Bonwill  and  Logan  crowns.) 
The  occluding  edges  or  surfaces  of  antagonizing  teeth  should 
be  removed  sufficiently  to  allow  ample  space  for  the  artificial 
crowns  or  to  favor  them  in  occlusion.  This  is  especially  necessary 
where  the  occluding  tooth,  in  the  absence  of  an  antagonist,  pro- 
trudes beyond  the  proper  line  of  occlusion.  When  the  approximal 
teeth  crowd  against  and  overhang  the  cervix  of  a  root,  so  that  the 
space  for  the  artificial  crown  at  the  occluding  surface  is  less  than 
at  the  prepared  cervix, — ^measured  from  mesial  to  distal  side, — • 
the  sides  of  the  root  should  be  trimmed  so  as  to  give  a  free  space 
between  it  and  the  sides  of  the  approximal  teeth.  The  approximal 
teeth  may  also  be  pressed  away,  or  a  small  portion  of  their  inter- 
fering surfaces  removed.      (See  Mgs.  26  and  27.) 


Fig.  26. 


Fig.  27. 


Corundum  or  composition  wheels  or  points  should  be  kept  wet 
and  cool  during  all  such  operations  in  the  mouth.  A  piece  of 
sponge,  held  against  the  wheel  with  clamping  pliers,  answers  the 
purpose  admirably,  and  also  protects  the  tongue  and  cheek  from 
injury. 

Special  Preparation  of  Badly  Decayed  Teeth  or  Roots. — The 
temporary  exposure  of  the  end  of  a  root  or  of  the  cervical  portion 
of  a  crown  for  the  purpose  of  facilitating  or  simplifying  a  crown- 
ing operation,  especially  in  the  adaptation  of  a  collar  or  band,  is 
effected  by  inserting  in  the  pulp-chamber  or  the  root-canal  a  piece 
of  gutta-percha  large  enough  to  admit  of  a  portion  being  brought 
over  against  the  investing  membranes,  to  compress  them  for  a  day 
or  more.     When  necessary  to  secure  attachment  for  the  gutta- 


SHAPING  TEETH  AND  Ji()()TS   F()l!  CROWN-WORK. 


39 


percha,  a  phig  of  wood  should  be  inserted  temporarily  in  the  root, 
£ind  the  gntta-percha  packed  around  it.  Roots  can  thus  be 
exposed  to  the  border  of  the  alveolar  process  if  desired.  In 
bicuspids  and  molars,  when  decay  extends  up  on  the  cervix  far- 
ther than  will  the  edge  of  the  artificial  crown  or 
the  collar,  the  gums  should  be  pressed  up  as  de- 
scribed, the  decay  removed,  retaining-pits  made, 
and  the  cavity  filled  with  amalgam  shaped  to  the 
contour  of  the  tooth  (Fig.  28).  In  incisors  and 
cuspids,  when  decay  has  destroyed  a  portion  of 
the  side  of  the  root,  a  tight-fitting  tube  of  a  metal 
to  which  amalgam  will  readily  adhere,  and  of  such 
size  as  to  admit  the  pin  of  the  crown,  can  be  inserted  up  the 
root-canal  and  the  upper  end  cemented  in  with  oxyphosphate  or 
oxychlorid,  and  the  lower  with  the  amalgam  forming  the  filling 
on  the  side  of  the  root.  In  such  a  case,  the  pin  should  be  tapered 
at  the  end,  and  inserted  in  the  canal  as  deeply  as  possible  beyond 


Fio.  29. 


yi 


Fig.  30. 


Fig.  31. 


Fig.  32. 


the  end  of  the  tube,  to  gain  additional  strength  by  distributing  the 
leverage  along  the  whole  line  of  the  root. 

In  setting  a  gold  cap-crov^m  on  a  badly  broken-dovTu  tooth  or 
root,  a  post  of  silver  or  iridio-platinum  wire  should  be  fitted  to 
the  root-canals  (Figs.  29,  30,  31,  and  32).  The  end  can  be  bent 
or  a  piece  of  silver  soldered  to  it.  The  post  should  then  be 
barbed  and  the  point  first  fastened  in  the  root  with  a  little  oxy- 
phosphate or  oxychlorid  of  zinc,  and  the  crovsm  built  dovra.  about 
two-thirds  its  length  with  a  quick-setting  amalgam,  to  be  shaped 
when  hard  and  then  roughened  to  furnish  a  better  attachment  for 
the  cement  with  which  the  crown  is  set,  Screws  may  be  used  as 
posts  to  support  the  amalgam.  In  such  cases  it  is  presumed  that 
the  gold  cap  will  entirely  cover  the  amalgam. 


PAET  II. 


ARTIFICIAL  CROWN-WORK. 


ARTIFICIAL  CROVYN-AVOPvK. 

Artificial  crown-work  affords  extensive  facilities  for  restoring 
the  crowns  of  natural  teeth,  and  furnishes  means  of  support  for 
bridge-work. 

Two  general  systems  are  presented, — the  porcelain  and  the 
gold.  The  porcelain  system  will  include  ready-made  porcelain 
crowns,  applied  with  or  without  collars,  and  the  gold  system  gold 
crowns  with  porcelain  fronts,  all-gold  crowns,  and  special  opera- 
tions in  crown-work. 


43 


THE  PORCELAIN  SYSTEM. 


CHAP  TEE   I. 

POKCELAIN  CEOWNS. 

PoECELAiisr  crown-work  is  practiced  by  many  dentists  almost 
exclusively,  excepting  only  the  occasional  insertion  of  a  gold  cap- 
crown  on  a  posterior  tooth.  The  reasons  for  this  are,  the  intricate 
character  of  the  construction  of  gold  crowns,  and  objections  to 
crowns  \\^ith  bands  or  collars. 

The  advocates  of  the  porcelain  system  claim  for  it  natural 
appearance,  restoration  of  contour,  strength,  and  cleanliness,  to- 
gether with  simplicity  of  construction  and  easy  adaptation  and 
attachment  to  the  root,  to  which  the  crown  is  hermetically  sealed. 

Porcelain  crowns  are  made  in  two  general  styles.  In  one  the 
crown  is  attached  to  the  root  by  a  pivot,  post,  or  screw,  one  end 
of  which  is  cemented  in  the  root  and  the  other  in  the  crown. 
Such  are  the  Gates-Bonwill,  Foster,  and  Howland-Perry  crowns. 
In  the  other  style,  one  end  of  the  pivot,  or  post,  is  baked  in  the 
porcelain  when  the  crown  is  made,  and  the  other  end  cemented 
into  the  root  when  the  crown  is  adjusted.  The  Logan  crown  is 
of  this  class. 

Special  advantages  are  claimed  for  each  of  these  several  forms 
of  crowns.  A  general  knowledge  of  the  different  methods  is 
therefore  essential  to  determine  the  adaptation  of  each  to  the 
requirements  of  a  case. 

The  preparatory  treatment  of  the  roots  respecting  the  process 

of  grinding,  trimming,  and  shaping  is  nearly  the  same  for  all 

porcelain  crowns.     A  plaster  model  and  "bite"  of  the  case  will 

aid  in  the  selection  of  a  suitable  crown  and  in  the  preliminary 

44 


THE  GATES-BON  WILL  CROWN. 


45 


Fig. 


fitting  to  the  root,  A  post  of  wood  or  metal  placed  in  and  left 
extending  from  the  root-canal,  and  then  withdrawn  in  the  impres- 
sion, will  give  the  line  of  the  canal  in  the  plaster  model.  Expos- 
ing the  end  of  the  root,  by 
pressing  the  gum  away  from  it 
with  gutta-percha  preliminary 
to  the  operation,  will  greatly 
assist  the  operator,  by  enabling 
him  to  avoid  accidental  lacera- 
tion of  the  adjoining  mem- 
branes, and  the  annoyance  at- 
tending their  bleeding,  besides 
permitting  him  to  carefully 
study  the  adjustment  and 
cementation  of  the  crown. 
The  obtaining  of  a  close  joint 
is  much  facilitated  in  all  forms 
of  porcelain  crowns  by  passing  a  disk  of  1)1  ack  marking-paper  over 
the  post  or  pin  which  is  to  retain  the  crown,  and  placing  the  crown 
in  position  on  the  root.  (See  Fig.  33.)  Cut  the  paper  in  a  strip, 
and,  to  admit  the  post,  form  holes  with  a  punch  as  shown  on 
margin  of  Fig.  33.  The  points  which  prevent  perfect  adjustment 
are  marked  on  both  root  and  crown,  either  of  which  can  be  dressed 
off  accordingly  as  seems  most  desirable.  Crowns  in  which  the 
post  is  cemented  will  first  be  described. 

THE    GATES-BONWILL    CROWN. i 

The  Gates-Bonwill  crown  is  made  entirely  of  porcelain.  It 
is  molded  with  a  concave  base  and  with  a  triangular  perforation 
for  the  reception  of  the  post.  The  perforation  passes  from  the 
bottom  of  the  base  to  the  center  of 
the  palatal  or  lingual  surface  in  in- 
cisors and  cuspids  (Fig.  34),  and  to 
the  center  of  the  grinding-surface  in 
bicuspids  (Figs.  35  and  36).  The 
molars  have  two  perforations,  placed  in  the  uppers  across  the  line 

'  Owing  to  their  great  similarity,  the  two  crowns  formerly  known  as  the  Bonwill 
and  the  Gates,  from  their  respective  inventors,  have  been  merged  in  one,  to  which 
the  name  Gates-Bonwill  has  been  applied. 


Fig.  34. 


46  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

of  the  arch  (Fig.  35),  and  in  the  lowers  in  that  line  (Fig.  36).  The 
openings  of  the  perforations  upon  the  exposed  surfaces  are  very 
slightly  countersunk. 

Fig.   35.  Fm.  36. 

,.<=x      r-^    ^rrr,   /«-lr^, 


47 


_  jiii 


;  The  posts  to  secure  this  crown  are  first  cemented  or  screwed 
into  the  root-canal.  The  crown  is  then  fitted  over  the  free  end  of 
the  post  and  attached  with  cement,  and  in  some  cases,  addition- 
ally, a  screw-nut  on  post. 

The  incisors  and  cuspids,  of  course,  require  one 
post;  the  bicuspids  usually  one,  sometimes  two;  the 
molars  two  posts.  The  form  of  post,  the  screw,  most 
commonly  used  is  illustrated  in  Fig.  37.  They  are 
usually  made  of  an  alloy  of  silver  and  platinum;  gold 
and  iridio-platinum  are  also  used. 

The  metliod  of  preparation  of  the  end  of  the  root 
and  canals  to  receive  and  retain  one  or  more  posts  to 
mount  the  Gates-Bonwill  crown  is  about  the  same  as  is  used  for  all 
similar  styles  of  crown.  The  end  of  the  root  is  trimmed  to  the 
gum-margin  in  the  front  teeth,  slightly  below  it  at  the  labial  side, 
to  hide  the  intended  union  of  porcelain  with  root.  A  slight  con- 
cavity is  also  formed  on  the  end  of  the  root,  as  shown  in  Fig.  40. 
The  length  of  the  root-canal  is  measured  with  a  root-canal  plugger 
and  its  flexible  gauge.  A  disk  of  rubber  dam  can  be  placed  on  the 
plugger  and  used  for  the  same  purpose.  By  this  means  the  proper 
length  for  the  post  is  determined.  The  dimensions  of  the  root 
determine  the  diameter.  Fill  that  part  of  the  end  of  the  canal 
which  will  not  be  occupied  by  the  post.  Enlarge  the  canal  with 
Gates-Glidden  drill  as  deep  as  required  to  accommodate  the  post  for 
the  crown  which  is  to  be  inserted.  I^ext,  with  a  gauge-plate,  de- 
termine the  size  of  the  post,  and  with  smaller-sized  fissure-burs 
gradually  ream  the  canal  to  a  dimension  which  the  post  will  fit 


THI<:  GATKS-nONWILI.   CROWN. 


47 


tightly.     The  screw-post  is  then  cemented  in  position  with  oxy- 

phosphate  or  oxychlorid  of  zinc. 

When  the  post  is  to  be  screwed  in  the  canal,  instead  of 
being  cemented,  the  How  screw-posts  and  appliances,  illus- 
trated in  Fiffs.  38  to  43,  had  best  be  nsed  as  here  described. 


Fig.  38. 


Fig.  39.        Fio.  40. 


Fig.  41. 


Fig.  42. 


Fig.  43. 


"1.  Set  gauge  on  a  Gates  drill  (Fig.  38)  to  one-half 
the  gauged  depth  of  the  canal,  and  drill  to  that  depth. 

"2.  Set  the  twist-drill  in  its  chuck  (Fig.  39)  to  project 
the  same  length  as  the  Gates  drill,  and  drill  the  root  to  ex- 
actly that  depth. 

"3.  Enlarge  the  mouth  of  the  canal  one-sixteenth  of  an 
inch  deep  all  around  to  near  the  margin  of  the  root,  as  shown 
in  Fig.  40,  using  square-end  fissure-bur  jSTo.  59,  and  then 
with  oval,  No.  94,  undercut  a  groove  lingually  and  at  the 
sides. 

"4.  Set  the  tap  in  its  chuck  (Fig.  41)  a  trifle  less  in 
length  than  the  drill,  oil  it,  and  carefully  tap  the  root  to  the 
gauged  depth. 

"5.  Insert  the  post  (Fig.  42)  in  its  chuck  (Fig.  43)  to 
the  exact  gauge  of  the  tap,  and  turn  the  thumb-screw  down 
hard  on  the  end  of  the  post,  then  screw  the  post  into  the 
root,  release  the  thumb-screw,  unscrew  the  chuck  a  half- 
turn,  bend  the  post  until  the  chuck  stands  in  center  line  with 
the  adjoining  teeth,  and  unscrew  the  chuck  from  the  post." 
The  appearance  of  posts  in  relation  to  roots  and  crowns  is  illus- 
trated in  Figs.  44,  45,  and  46. 


48 


ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 


In  single-rooted  teeth,  when  desirous  of  locking  the  post  in  the 
root  to  prevent  turning  of  either  post  or  crown,  Dr.  How  suggests 
to  take  a  ISTo.  2  round  bur  and  drill  less  than  an  eighth  of  an  inch 
into  the  root  close  to  and  cutting  slightly  into  the  post,  and  insert 
a  quarter  of  an  inch  length  of  wire  as  shown  in  Eig.  47. 


Fig.  45. 


Fig.  46. 


Fig.  47. 


Pig.  48. 


'A 


If  a  root  is  much  wasted,  leaving  thin  walls,  the  preceding  gaug- 
ing and  locking  process  will  result  in  the  secure  and  safe  setting 
of  a  screw-post  to  be  packed  around  with  amalgam,  as  shown  in 
Fig.  48,  and  on  this  connection  a  suitable  cro^vn  can  be  securely 
mounted. 

When  grinding  the  selected  porcelain  crown  to  position  on  the 
root,  the  end  of  the  post  should  be  bent  or  trimmed  so  as  to  allow 
the  cro'wn  to  assume  any  desired  position.      (Fig-  47.) 

Attachment  of  Croivii  to  Boot. — Amalgam,  oxyphosphate,  or 
gutta-percha  is  used  for  the  purpose. 

To  attach  with  amalgam,  place  the  amalgam  high  enough  up  on 
the  root  and  post  to  fill  the  base  of  the  crown. 

The  crown  should  be  tried  on,  and  forced  home  with  the  aid 
of  an  -adjuster,  removing  the  surplus  amalgam  if  too  much,  or  add- 
ing to  if  not  enough.  Kemove  and  dry  the  crown,  and  fill  up 
simply  the  undercut  cavity  in  the  palatal  face  if  an  incisor,  or 
the  depressions  in  the  crowns  of  bicuspids  or  molars,  allomng  a 
very  little  to  extend  into  the  cervical  base,  and  force  the  crown 
home  with  the  adjuster.  It  requires  considerable  force  to  set  one 
of  these  crowns, — a  force  which  cannot  be  applied  with  a  mallet 
without  danger  of  loosening  or  displacing  the  crown.  Steady 
pressure  with  slight  rotation  mil  carry  the  crown  into  place,  if  tlie 
amale'am  is  not  too  hard  or  there  is  not  too  much  of  it.     I^ext  hold 


TllK  FOSTER  AXJ)  IIUWLAND-PKJIRY  CROWNS.  49 

the  crown  with  the  fingers  and  througli  the  hole  in  the  crown  pack 
amalgam  mixed  stiff  around  the  pin,  assisted  by  cotton  or  bibulous 
paper  to  remove  the  surplus  mercury.  If  a  nut  is  used  on  the  end 
of  the  post,  remove  enough  amalgam  to  make  room  for  the  nut, 
screw  the  nut  to  position  and  cover  with  amalgam.  A  quick- 
setting  amalgam  should  be  used. 

Oxy phosphate  cement  is  preferred  at  present  to  attach  all  cro"\vns 
of  this  style.  The  posts  are  carefully  dried,  the  cement  mixed  to 
the  consistence  of  a  thick  cream,  the  crown  adjusted  on  the  root, 
and  the  nut  placed  on  the  post  and  screwed  to  position  in  the 
crown. 

When  a  nut  is  not  used  on  the  post,  the  crown  must  be  held  in 
position  until  the  cement  sets  sufficiently  hard  to  prevent  displace- 
ment. 

Gutta-percha,  Avhen  used,  is  heated  together  with  the  crown,  and 
applied  the  same  as  oxyphosphate. 

When  the  cement  is  set,  any  space  around  or  above  the  nut 
on  the  post  should  be  filled  mth  either  amalgam  or  gold  to  the 
surface  of  the  crown. 

THE    FOSTER    CROWN. 

The  Foster  crown  (Fig.  49),  which  in  general  form  is  similar 
to  a  crown  introduced  by  Dr.  H.  Lawrence,  of  Philadelphia,  in 

Fig.  49. 


il849,  also  resembles  the  Gates-Bonwill,  but  has  less  concavity  at 
the  base.  The  crown  is  attached  to  the  root  by  a  headed  screw 
(Fig.  50)  or  a  screw  with  a  nut. 

The  How  screws  and  instruments  (Fig.  51)  are  best  adapted  for 
use  with  these  crowns. 

THE    HOWLAND-PERRY    CROWN. 

This  crown,  which  is  similar  in  principle  to  one  originally  in- 
troduced by  Dr.  C.  H.  Mack,  was  devised  by  Dr.  S.  F.  Howland 

6 


50 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 


and  improved  bj  Dr.  S.  G.,  Perry.  It  is  attached  like  tlie  Gates- 
Bonwill  crown,  with  posts  which  are  first  cemented  in  the  root 
and  then  in  the  crown.  The  base  is  given  a  curve  approximating 
that  of  the  line  of  the  margin  of  the  gum,  with  the  labial  portion 


Fig.  51. 


Fig.  52. 


Fig.  53. 


Fig.  54. 


projecting  slightly  above  it,  to  include  a  little  of  the 
cervix.  The  cavity  in  the  porcelain  is  given  a  size, 
form,  and  position  which  will  receive  the  posts  extend- 
ing from  the  root  without  impairing  the  strength  of  the 
crown-walls.  Thus  they  are  made  round  in  the  incisors 
and  cuspids  (A,  Eig.  52),  and  oval  in  the  bicuspids  (A, 
Fig.  53). 

The  method  of  setting  this  crown  is  to  first  shape  the  end  of 
the  root  approximately  to  correspond  to  the  base  of  the  porce- 
lain crown,  and  then  accurately  fit  the  porcelain  crown  to  the 
end  of  the  root.  Eit  a  post  to  the  root-canal  that  will  also  fit  the 
cavity  in  the  porcelain.  Partly  fill  the  root-canal  with  oxyphos- 
phate,  and  press  the  post  in  place  with  pliers.  Fill  the  cavity  in 
the  crown  with  cement,  press  to  place,  and  hold  carefully  in  posi- 
tion until  the  cement  sets  (Fig.  54).  Some  prefer  to  cement  the 
post  first  and  the  crown  afterward. 


THE    LOGAN    CROWN. 

In  the  Logan  crown  the  platinum  post  or  pin  is  baked  in  the 
body  of  the  porcelain.  The  base  of  the  crown  is  made  concave, 
to  facilitate  its  adjustment  to  the  end  of  the  root,  and  to  give  the 
cement  a  more  reliable  form. 

The  preparation  of  a  root  for  a  Logan  crown  is,  in  general, 
similar  to  that  for  the  Gates-Bonwill  crown.     The  root-canal  is 


THE  LOGAN  CROWN. 


51 


enlarged,  and  shaped  so  that  the  post,  if  possible,  at  least  at  its 
point,  will  fit  tightly.  Gutta-percha  or  oxyphosphate  is  used  for 
cementing  in  preference  to  amalgam. 

The  Logan  crown,  now  so  extensively  used,  is  the  invention  of 
Dr.  M.  L.  Logan.     The  method  of  mounting  is  explained  in  all 
its  details  in  the  following  article  by  Dr.  W.  S.  How: 
Fig.  55.       Fm.  66.  Fio.  57.  Fig.  68. 


"Fig.  55  shows  a  superior  right  central  root,  an  end  appear- 
ance of  the  same,  and  a  Logan  crown,  front  view.     Fig.  56  ex- 
hibits, at  a  right  angle  to  the  plane  of  the  first  figure,  the  same 
Fig.  69.  Fig.  60.  Fig.  61.      Fig.  62. 


root,  its  end,  and  the  Logan  crown,  side  view.  In  both  figures 
the  root-canal  is  supposed  to  have  been  first  drilled  to  a  gauged 
depth  with  an  engine  twist-drill,  ISTo.  154,  and  then  enlarged  by 
means  of  a  fissure-bur,  ISTo.  70,  to  the  tapering  form  shown;  the 
walls  being  subsequently  grooved  with  an  oval  bur,  l^o.  90.  The 
enlarged  section,  Fig.  5Y,  shows  the  crown  adjusted  on  the  root 


52 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


by  means  of  cement  or  gntta-perclia,  which,  surrounds  the  post 
and  fills  all  the  spaces  in  the  root  and  crown.     Fig.  58  shows  the 


Fig.  63. 


Fig.  64. 


FiQ.  65. 


Fig.  66. 


completed  crown.     Fig.   59  exhibits  a  bifurcated  bicuspid  root^ 
its  end  aj^pearance,  and  a  Logan  crown  adjusted  to  the  root.     Tig. 


Fig.  67.     Fig.  6R. 


Fig.  69. 


F]G.  70. 


Fig.  71. 


Fig.  72. 


60  illustrates  the  best  manner  of  bending  the  post.     Fig. 

61  shows  a  split  post,  and  its  adaptation  to  a  bifurcated 
bicuspid  root  is  seen  in  Fig.  62.  Figs.  63  and  64  exhibit 
the  mode  of  mounting  the  Logan  crown  on  a  superior  molar 
root,  and  Figs.  65  and  66  the  same  crown  in  its  relations 
to  an  inferior  molar  root. 

"The  preceding  figures  clearly  present  to  the  mind's  eye 
of  the  expert  dentist  the  essential  features  of  the  Logan 
crown  and  the  method  of  mounting  it, 

"The  details  are  as  follows:  The  root  should  first  be 
measured  through  its  canal  from  the  cervical  opening  to  the 
apical  foramen.     This  may  be  accurately  done  with  a  gauge  ad- 
justable on  a  delicate  canal-explorer  (Fig.   67).     The  same  de- 


THE  LOGAN  CliO  WN. 


53 


Fig.  73. 


vice  serves  to  measure  the  distance  from  the  apex  to  which  the 
canal    should    then    be    filled    (Fig.    68).     It    also    gauges    the 
depth  to  which  the  drill  may  be  carried.     The  proper  degree  of 
enlargement  from  the  bottom  of  the  drilled  hole 
will,  of  course,  depend  on  the  observed  size  and 
character  of  the  root.     For  preparing  the  roots, 
the  Ottolengui  root-reamers  (Fig.  72)  and  facers 
(Fig.  Y3)  are  very  desirable  instruments.     The 
reamers  are  made  in  three  sizes  to  correspond 
with  the  Logan  pins.     With  a  root-reamer  of  the 
appropriate  size,  the  root-canal  is  enlarged  to  fit 
the  pin  along  its  whole  length,  and  so  hold  the 
crown    firmly    independently    of    the    cement. 
With  a  root-facer  a  labial  slope  is  given  to  the 
root-end,  so  that  the  crown  neck  shall  fit  under 
the  edge  of  the  gum.      Figs.  74  to  78  show  the 
method  and  its  result;  the  cross-section  shows  how  the  cement  in- 
cases the  pin.     The  suitable  preparation  of  the  bifurcated  roots 


Fig.  76. 


Fig.  77. 


Fig.  78. 


/^ 


of  some  bicuspids  and  of  all  the  molars  is  a  matter  involving 
difficulties  of  an  unusual  character  and  requiring  good  judgment. 


54 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  feasibility  of  splitting  the  post  of  a  Logan  crown  to  adapt 
it  to  the  bifurcated  root  of  a  bicuspid  is  shown  by  Figs.  61  and  62. 
This  example  directs  attention  to  the  peculiar  shape  of  the  post^ 
in  which  there  is  effected  such  a  distribution  of  the  metal  that 
its  greatest  strength  is  in  the  line  of  the  greatest  stress  that  will 
in  use  be  brought  to  bear  on  the  crown,  while  the  least  metal  is 
found  at  the  point  of  the  least  strain;  the  applied  part  of  the  post 
being  in  outline  nearly  correspondent  to  that  of  the  root  itself. 
The  root-canal  is  likewise  conformably  enlarged  to  receive  the 
largest  and  stiffest  post  which  the  size  and  shape  of  the  root  will 
permit. 

"The  fitting  of  a  Logan  crown  to  a  root  may  be  done  with  a 
wet  stump-wheel  in  the  engine  hand-piece,  A  safe-side  crown 
corundum- wheel  (Fig.  Y9)  can  be  used  in  the  same  manner.  It 
also  affords  the  greatest  facility  for  the  slight  touches  required  to 
abrade  the  thin  cervical  borders  of  the  crown,  which  may  by  this 
means  be  done  without  encroachment  on  the  post. 


Fig.  79. 


Fig.  80. 


"By  the  old  method  of  adapting  pivot-teeth  to  roots,  the  close 
fitting  of  the  crown  precluded  the  use  of  a  plastic  packing,  because 
its  thinness  over  the  surface  of  the  joint  made  the  packing  liable  to 
break  loose  under  the  shock  and  strain  of  use.  The  recess  in  the 
Logan  crown  obviates  this  defect  by  providing  a  receptacle  for  a 
considerable  interior  body  of  cement  that  will  be  deep  enough  to 
be  self-sustaining  internally,  and  yet  allow  the  peripheral  portions 
of  the  root  and  crown  to  approach  each  other  so  closely  that, 
though  only  a  film  of  packing  remain,  it  will  still  be  strong  enough 


THE  LOGAN  CROWN.  55 

to  insure  the  persistent  tightness  of  the  joint.  This  annular  boss, 
if  formed  of  amalgam,  also  adds  strength  in  some  cases  to  the 
mount. 

"When  enough  of  the  natural  crown  remains,  it  is  well  to  leave 
standing  some  of  the  palatal  portion,  and  cut  the  root  under  the 
gum-margin  at  only  the  labial  part,  as  shown  by  Fig.  69.  The 
safe-side  crown  wheel  is  especially  useful  in  such  cases  (Fig.  80). 
Thus  the  labial  joining  of  the  root  and  crown  will  be  concealed,  and 
the  other  parts  of  the  joint  will  be  accessible  for  finishing  and 
keeping  clean  (Fig.  70).  The  Logan  crown  may  be  ground  until 
a  large  part  shall  have  been  removed  for  adaptation  to  the  occlud- 
ing tooth  or  teeth  without  seriously  impairing  its  strength  (Fig. 
71).  This  crown  also  in  such  cases  maintains  the  translucency 
which  is  one  of  its  peculiar  excellences,  owing  to  its  solid  porcelain 
body,  and  the  absence  of  a  metallic  backing  or  an  interior  largely 
filled  with  cement  or  amalgam. 

"The  distal  buccal  root  of  the  natural  superior  molar  is  nearly 
always  too  small  to  receive  a  post  of  any  useful  diameter,  and 
therefore  the  Logan  superior  molar  crown  has  but  two  posts,  which 
like  those  of  the  inferior  molar  crown  are  square,  and  thus  may  be 
easily  barbed,  as  may  also  the  ribbed  posts  of  the  crowns  for  the  an- 
terior tooth-roots.  These  posts  are  large  enough  in  all  the  Logan 
crowns  to  answer  in  any  given  case,  and  can  of  course  be  easily  re- 
duced to  suit  thin  or  short  roots. 

"Any  of  the  cements  or  amalgams  may  be  used  in  fixing  these 
crowns,  but  good  gutta-percha,  softened  at  a  low  heat  and  quickly 
wrapped  around  the  heated  crown-post,  which  is  at  once  seated  in 
the  joot,  forms  the  best  mounting  medium,  and  has  the  great  ad- 
vantage of  permitting  a  readjustment,  or,  if  need  be,  the  ready  re- 
moval of  the  crown  by  grasping  it  with  a  pair  of  hot  pliers  or 
forceps,  and  holding  it  until  the  gutta-percha  is  sufficiently  soft- 
ened." 

Method  of  Fitting  Logan  Grown  hy  Model  of  Natural  Tooth. 

First  prepare  the  face  of  the  root  to  be  cro'^vned  as  desired, 
(A,  Fig.  81),  and  having  selected  a  suitable  crown,  B,  bend 
the  pin,  if  necessary,  so  as  to  make  a  proper  alignment. 

l^ext  place  a  piece  of  paraffin  wax  around  the  pin  next  to 
the  porcelain,  G,  then  take  JSTo.  60  tin  foil  and  trim  a  disk  a 


56 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 


EiG.  81. 


little  larger  than  the  abutment,  ~D,  j)ierce  the  center  of  the 
disk  with  the  crown  pin  or  instrument  shown  in  the  mar- 
gin, E,  pushing  the  disk 
down  until  it  touches 
the  wax;  place  the  crown 
on  the  root  and  force 
it  to  place,  F,  the  wax 
driving  the  tin-foil  disk 
to  a  perfect  apposition 
with  the  abutment  of 
the  root. 

Remove  the  crown 
with  the  wax,  holding 
the  tin-foil  disk  in  posi- 
tion, and  with  a  pair  of 
sharp-pointed  scissors 
snip  the  edges  of  the 
disk  slightly  all  around. 
Place  a  small  pellet  of 
wax  on  the  end  of  the 
pin,  H,  then  insert  the 
pin  up  to  the  porcelain 
in  quick-setting  plaster, 
I;  after  the  plaster  hard- 
ens warm  the  crown  and 
remove  it,  the  snipped 
edges  of  the  disk  serv- 
ing to  hold  it  in  position ; 
clean  off  the  wax  and 
replace  the  crown  on  the 
model,  and  you  have  a 
perfect  metallic-surfaced 
model  of  the  abutment 
of  the  root  to  which  to 
grind  with  a  perfect  view  of  every  surface  of  the  root,  the  wax 
which  was  on  the  end  of  the  pin  allowing  it  to  penetrate  the  plaster 
as  the  porcelain  is  ground  away.  By  this  method  a  Logan  crown 
can  easily  be  made  to  fit  perfectly. 


PORCELAIN  CROWNS  AND  CROWNS   WITIIOI'T  ('OJ.LARS.       57 

REMARKS    ON    THE    USE    OF    PORCELAIN    CROWNS    AND 
CROWNS    WITHOUT    COLLARS. 

Porcelain  crowns  have  some  decided  advantages.  They  are 
especially  useful  in  many  cases  where  an  inexpensive  or  easily 
adjusted  crown  is  required;  or  where  some  pathological  condition 
limits  the  prohable  durability  or  permanence  of  any  operation. 
In  the  insertion  of  porcelain  cro^vns,  the  removal  of  the  whole  or 
a  part  of  the  natural  cro^vn,  which  could  be  utilized  to  some 
extent  as  a  foundation  by  other  systems,  has  given  rise  to  various 
objections.  If  the  natural  crown  is  entirely  cut  away  the  pin,  or 
post,  upon  which  almost  the  entire  support  of  the  artificial  crown 
is  thrown,  exerts  great  leverage  in  the  root-canal  when  no  band 
or  brace  is  present  on  the  exterior  of  the  root  to  relieve  the  strain. 
With  the  whole  force  of  mastication  bearing  directly  upon  these 
pulpless  roots,  whose  disintegration  is  slowly  but  constantly  pro- 
gressing, the  inevitable  result  can  well  be  conjectured.  Sooner  or 
later  they  are  fractured,  and  their  usefulness  as  a  foundation 
ended.  Then,  again,  if  porcelain  crowns  are  attached  with 
amalgam,  the  discoloration  of  the  line  of  union  wath  the  root,  if 
subsequently  exposed,  is  disfiguring.  These  facts,  and  the  lack  of 
strength  incident  to  some  forms  of  construction,  are  the  principal 
objections  urged  against  porcelain  crowns  as  ordinarily  inserted. 


CHAPTEE  11. 

POECELAIN  CEOWN  WITH  GOLD  COLLAR  ATTACHMENT. 

A  GOLD  collar,  either  seamless  or  soldered,  can  be  used  advan- 
tageously in  combination  witb  many  of  the  porcelain  crowns. 

The  root  having  been  properly  prepared,  a  collar  is  adjusted 
and  adapted  to  it  the  same  as  for  a  gold  collar  crown.  (See  page 
TO.)  The  porcelain  crown,  the  base  of  which  should  be  fully  as 
large  as  the  end  of  the  root,  is  then  ground  even  with  the  cervical 
walls,  and  fitted  into  the  collar,  which  should  be  trimmed  and 
burnished  to  the  form  of  the  crown.  Dr.  Townsend's  fusible 
metal  die,  used  in  the  following  manner,  facilitates  the  applica- 
tion of  a  collar  to  a  Logan  crown  (Fig.  82).  Enlarge  the  root- 
EiG  82  canal  to  receive  the  Logan  pin.  Grind  a  Logan 
/'\  crown  to  fit,  and  articulate  it.     Construct  a  band 

/     \  of  'No,  30  gold  (or  of  No.  32  crown-metal)  wide 

enough  to  project  beyond  the  end  of  the  root  say 
•        -^2   of  an  inch.     Cut  a  wooden  peg  about  an  inch 

long  and  taper  one  end  of  it 
1  to  the  general  size  and  shape 
of  the  pin  in  the  Logan  crown. 
Place  the  band  on  the  root,  in- 
sert the  peg  in  the  canal,  and 
imranB —  «    ,  o   i  .  o  ■c>   -i,,    n^  .  ,  fiU  W>  thc  baud  with  Melotte's 

I  :M     1.  Socket.  2.  Fusible  Metal.  y 

II  ::m  moldine  or  plaster,  pressing  it 
ll||_^___.--r^l^   closely  about  the  peg.     Remove  all  together,  and 

^te>    1^    hold  the  die  over  the  flame  of  an  alcohol  lamp  to 

^-  :^     melt  the  fusible  metal.     "When  melted,  place  the 

K  ^      socket  side  of  the  band  or  collar  and  wooden  plug 

i#         that  enters  the  root-canal  downward  on  the  surface 

of  the  metal;   cool  and  remove  the  moldine   or 

plaster,  and  plug.     This  gives  a  tight  grasp  on  the  lower  end  of 

the  band  and  does  not  allow  it  to  change  shape.     While  fitting  the 

crown  into  it,  place  the  crown  in  the  band,  allowing  the  pin  to 

58 


PORCELAIN  CROWN  WITH  GOLD  COLLAR  ATTACHMENT.     59 

enter  the  socket.  Drive  clown  with  a  mallet  till  the  porcelain 
comes  in  contact  with  the  metal.  In  this  way  you  stretch  the 
gold  around  the  porcelain;  now. burnish  down'  tightly.  If  this 
work  is  carefully  done,  the  articulation  should  be  the  same  as 
before  the  band  was  put  on.  Melt  fusible  metal  to  relieve  the 
collar  and  crown.  This  method  of  setting  a  porcelain  crown 
makes  a  strong  operation. 

Enough  of  the  collar  should  be  trimmed  away  at  the  labial 
portion  to  prevent  too  conspicuous  exposure  of  the  gold  (Fig.  83). 

This  collar  combination  is  available  in  very  difficult  cases,  as, 
for  instance,  when  a  root  is  decayed  upon  one  side  far  beneath  the 
gum,  as  seen  in  Fig.  84. 

Fig.  83.  Fig.  84.  Fig.  85.  Fig.  86. 


Such  an  operation,  when  completed,  would  appear  in  vertical 
section  like  Fig.  85,  and  a  view  in  perspective  would  resemble 
Fig.  86.  The  collar  is  also  very  useful  wherever  the  root  and 
crovoi  are  not  made  flush  and  smooth  at  every  point,  as,  if  practi- 
cable, they  should  always  be. 

METHOD  OF  MOUNTING    A    LOGAN    CROWN    WFTH    A    BAND 

AND  CAP. 

Prepare  the  root  in  the  usual  way  for  banding.  (See  Fig.  87, 
front  view,  and  Fig.  88,  side  view.) 

Grind  the  abutting  surface  of  the  crown  to  fit  the  root  under 
the  free  margin  of  the  gum,  along  the  labial  face  only.  (See 
Figs.  87,  88,  a  to  I.) 

Cut  the  crown  away  slightly  at  the  lingual  surface,  so  as  to 
leave  a  space  between  it  and  the  end  of  the  root.     (See  Fig.  89,  c.) 


60 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Make  a  band  wide  enough  only  to  give  a  good  hold  on  the 
root,  but  not  to  extend  beyond  the  margin  of  the  gum  to  fit  the 
root,  and  trim  off  even  with  the  end  of  it.  (See  Fig.  89,  d.)  After 
Fig  87  fitting  the  band  properly,  remove  it  and  -^^^ 
solder  a  piece  of  pure  gold  plate,  say  about 
ISTo.  34,  on  the  outer  end.  (See  Fig.  89,  e.) 
This  can  be  done  quickly  by  placing  the 
plate  in  the  hand  and  pressing  the  band 
onto  it  with  the  thumb  for  a  fit,  then  sol- 
dering in  the  flame  of  a  Bunsen  burner. 
Punch  a  small  hole  through  the  plate  to 
take  the  pin  in  the  crown,  and  replace  in 
position  on  the  root  after  trimming  off 
the  exposed  edges.  ISTow  take  a  piece  of 
thin  pure  gold,  say  ISTo.  34  or  36,  with  ears  as  shown  in  Fig.  90,  f, 
punch  a  hole  through  it,  slide  it  over  the  pin  of  the  Logan  crown, 
and  burnish  tightly  to  the  base  of  the  crown.  (See  Fig.  90.) 
]N"ext  warm  the  pin  and  place  a  sufficient  quantity  of  Parr's  fluxed 

Fig.  89. 


Fig.  90. 


wax  around  it  as  shown  by  dotted  lines.  Fig.  90.  Replace  the 
Logan  crown  on  the  root  (with  the  cap  in  position),  force  home 
until  the  labial  edges  of  root  and  crown  meet,  obtain  the  proper 
alignment,  and  cool  and  harden  the  wax  by  using  a  napkin  with 
ice-water.  Then  remove  the  crown  and  cap  together,  held  in 
proper  relative  position  by  the  wax.  (See  Fig.  91.)  Trim  off  the 
surplus  wax  and  invest.  (See  Fig.  92.)  Remove  all  the  wax 
possible  between  the  crown  and  the  band,  and  flow  20-carat  gold 
solder  into  the  space.     The  wax  which  will  necessarily  remain, 


PORCELAIN  CROWN  WITH  COLD  COLLAR  ATTACHMENT,     fjl 


being  fluxed,  will  carry  the  solder  into  every  crevice  and  give  tlie 
crown  great  strength.  Finish  the  band  and  the  soldered  edges, 
and  the  result  will  be  a  strong  and  perfectly  aligned  crown. ^ 

Should  an  unusual  alignment  of  the  porcelain  crown  with  the 
root  be  required  and  the  position  of  the  pin  interfere  with  securing 
it,  vary  the  process  as  follows:  When  the  piece  of  thin  gold  has 


Fig.  91. 


Fig.  92. 


been  fitted  to  the  base  of  the  crown  as  shown  in  Fig.  90,  cut  off 
the  pin  close  to  the  surface  of  the  gold  and  cement  the  gold  to  the 
stump  of  the  pin  with  wax.  Fit  the  cut-off  pin  in  the  root-canal 
and  to  the  cap,  cement  pin  and  cap  together,  remove  and  solder, 
l^ext  place  a  proper  quantity  of  wax  on  the  surface  of  the  cap, 
insert  in  the  mouth  and  adjust  the  crown  mth  the  gold  on  its  base 


Fig.  98. 


Fig.  94. 


in  position  against  the  wax  to  the  surface  of  the  cap.  Then  re- 
move cap  and  crown,  invest,  and  solder  the  same  as  previously 
described  and  illustrated  in  Fig.  92. 

Dr.  E.  C.  Kirk,  of  Philadelphia,  uses  for  bicuspids  and  molars 
a  Foster  crown  in  combination  with  a  collar  (Fig.  93).     A  collar 

lA  method   quite   similar   to    that  just   shown,   but   omitting   the  band,   was 
described  by  Dr.  Gordon  White  in  the  Dental  Cosmos  for  January,  1893. 


62  ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 

is  made,  and,  on  being  fitted  to  the  root,  is  cut  narrow  on  the 
buccal  side,  and  left  wide  on  the  palatal,  so  that  it  shall  extend 
nearly  to  the  cusp  of  the  crown  when  finished  (Fig.  94).  (The 
seamless  gold  collars  are  well  suited  for  this  style  of  crown.) 

The  crown  selected  should  have  a  somewhat  greater  circum- 
ference at  the  base  than  the  collar,  so  that  when  ground  down 
somewhat  conically  on  its  lingual  and  approximal  surfaces  it 
can  be  tightly  adjusted  to  the  collar.  If  a  crown  smaller  than 
the  collar  is  used,  a  tight  joint  cannot  be  made.  The  screw  is 
fitted  so  that  it  shall  hold  the  crown  in  proper  relations  with  the 
root.  The  screw  and  crown  are  then  removed,  the  parts  dried, 
and  the  root-canal  filled  with  a  slow-setting  oxyphosphate  cement, 
mixed  thin.  The  crown  is  then  pressed  into  its  position,  the 
surplus  cement  flowing  through  the  opening  in  the  porcelain  and 
filling  up  any  interstices  around  or  between  the  band,  the  root, 
and  the  crown.  The  screw  is  then  driven  into  position,  and  when 
the  cement  is  set  perfectly  hard  the  head  of  the  screw  or  the  nut 
on  it  is  notched  to  form  a  retaining-pit,  and  the  countersink  of 
the  crown  filled  with  gold. 

Dr.  C.  S.  W.  Baldwin  caps  the  root  and  attaches  a  Logan  crown 
in  the  following  manner: 

First,  the  root  is  shaped,  the  outer  margin  beveled  about  the 
thickness  of  the  gold  used,  to  give  a  proper  form  for  close  adapta- 
tion of  a  cap.  Then  an  impression  is  taken  and  a  die  made  in 
the  gold  seamless  cap  method  (see  Chapter  VII).  To  strike  up 
the  cap,  place  ISTo.  32  gauge  gold  plate  on  a  cushion  of  lead,  hold- 
ing the  die  firmly  on  the  gold  where  you  wish  to  produce  the  cap, 
and  strike  until  the  required  depth  is  secured  before  removing  it. 
This  drives  the  gold  and  die  into  the  lead,  forming  a  female  die 
and  a  perfect-fitting  cap  at  once,  in  less  time  than  is  occupied  in 
describing  the  process.  Trim  the  edges  to  fit  the  festoon  of  the 
gum,  and  drill  a  hole  from  the  inner  side  for  the  pin,  leaving  the 
raggedness  made  by  drilling  to  catch  in  the  cement.  Place  the 
cap  on  the  root  and  fit  the  porcelain  crown  accurately  to  it  in  the 
desired  occlusion  and  position.  A  Logan  crown  can,  with  little 
grinding,  be  made  to  do  good  service  (Fig.  95).  A  crown  having 
the  H -shaped  pin,  but  square  on  the  edge,  like  some  of  the  early 
patterns  of  Logan  or  Bonwill  crowns,  would  reduce  the  time  of 
setting  and  give  best  results.     Having  polished  the  edges  of  the 


PORCKLjAIN  CROWN  WITH  GOLD   COLLAR  ATTACHMENT,     gg 

cap,  the  crown  is  adjusted  as  follows:  Place  oxyphosphate 
cement  in  the  countersunk  portion  of  the  porcelain,  and  with  the 
gold  ferrule  or  cap  in  place,  properly  adjust  the  crown.  When 
the  oxyphosphate  is  hard,  remove  the  crown  and  cap  and  solder 
the  pin  to  the  inside  of  the  cap,  with  a  very  small  amount  of  soft 
solder, — tin  and  lead, — using  muriate  of  zinc  as  a  flux,  a  few 
blasts  of  the  blow-pipe  being  all  that  is  required.  Fill  the  root- 
canal  and  the  inside  of  the  cap  with  oxyphosphate  and  press  the 
crown  to  place  (Fig.  96). 


Fig.  95. 


Fig.  96. 


Fig.  97. 


Fig.  98. 


In  most  cases  the  gold  band  will  be  invisible  and  below  the  free 
margin  of  the  gum.  Cases  may  occur  where  the  anterior  teeth 
are  prominent,  and  it  will  be  necessary  to  cut  away  the  top  of  the 
cap  in  front,  allowing  the  porcelain  to  come  directly  in  contact 
with  the  root,  the  band  going  deeper  than  in  ordinary  cases,  which 
prevents  the  appearance  of  gold  (Fig,  97). 

Dr.  Bonvdll's  plan  is  to  cap  the  tooth  vidth  a  platinum  or  gold 
cap  having  a  slot,  into  which  the  pin  passes  as  it  is  slipped  on  the 
root  (Fig.  98).  The  crown  is  then  fastened  on  the  post  and  cap 
with  amalgam. 

Dr.  S.  S.  Stowell  suggests  the  following  method  of  applying 
porcelain  crowns,  with  or  without  a  countersunk  base  in  which 
a  post  can  be  cemented,  forming  what  he  calls  the  "Simplicity 
Crown" : 

The  end  of  the  root  is  prepared  in  the  usual  manner  and 
slightly  countersunk.     The  porcelain  crown  (an  ordinary  pivot. 


64 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


an  English  tube  tooth,  or  a  Ilowland-Perry  crown)  is  then  fitted 
in  position,  and  the  glazed  surface  of  the  base  and  cavity  removed 
to  secure  better  adhesion  of  the  cement.  A  How  screw-post, 
preferably  of  iridio-platinum,  is  inserted  in  the  root  in  alignment 
with  the  cavity  in  the  croAvn.  After  the  screw-post  is  set,  a 
groove  is  cut  on  the  end  of  the  root,  around  the  post,  with  small- 
sized  engine-burs.     This  groove  is  filled  with  copper  amalgam,  the 


Fig.  99. 


crown  placed  on  the  root,  and  the  excess  of  amalgam  pressed  out. 
The  crown  is  then  removed,  filled  with  oxyphosphate  cement,  and 
pressed  back  in  place.  The  excess  of  cement  exudes  on  all  sides, 
and  carries  with  it  any  excess  of  the  amalgam.  The  crown  is  held 
in  position  until  the  cement  sets.  Fig.  99  shows  an  incisor  and  a 
bicuspid  made  by  this  plan,  when  ready  for  adjustment;  also  a 
sectional  view  of  the  completed  incisor. 


OHAPTEK    III. 

PORCELAIN  CROWNS  WITH   RUBBER  OR   VULCANITE 
ATTACHMENT. 


Fig.  100. 


Fig.  100  illustrates  the  formation  of  such  a  crown.  The  root, 
when  prepared,  extends  at  the  palatal  side  a  little  below  the  line 
of  the  gum  (A)  at  the  point  B.  A  plate  tooth 
(C)  is  ground  and  fitted  to  the  root.  An  iridio- 
platinum  post  is  then  fitted  to  the  root,  flattened 
slightly  and  bent  at  D,  and  riveted  to  the  tooth. 
The  proper  alignments  of  the  tooth  and  post  to 
the  root  are  then  obtained,  and  they  are  invested 
and  the  post  soldered  and  strengthened  at  the 
point  D.  The  backing  is  then  grooved  and 
notched  slightly,  wax  applied,  the  crown  ad-  r 
justed  to  the  root,  and  the  wax  shaped  so  as  to  a\ 
form  a  foundation  and  overlapping  edge  at  the 
palatal  portion  (E),  and  also  extend  around  the 
post  up  the  canal.  The  crown  is  next  removed, 
invested  in  a  fiask,  packed  with  rubber,  and 
vulcanized.  In  trimming  and  finishing,  the 
rubber  is  allowed  to  form  a  partial  band  or 
collar  around  the  palatal  portion  of  the  root,  where  it  will  not 
show.     It  is  then  cemented  on  to  the  root  with  oxy phosphate. 

A  Temporary  Crown. — Fit  in  the  root-canal  a  post  of  metal, 
preferably  made  of  German  silver  wire.  Let  the  post  extend 
out  of  the  canal  about  one-eighth  of  an  inch  and  roughen  the 
sides.  Perforate  a  disk  of  the  heaviest  pattern  tin  with  the  post, 
and  fit  the  tin  to  the  end  of  the  root.  Fit  a  suitable  two-pin. 
rubber  porcelain  tooth  to  the  disk.  Groove  out  the  porcelain, 
if  necessary,  to  fit  over  the  post.  Wax  the  porcelain  tooth  to 
the  disk  and  post,  remove  and  invest  in  plain  plaster  of  Paris. 
Remove  the  wax  with  boiling  water,  and,  in  its  place,  melt 
fusible  metal  and  instantly  press  down  firmly  into  the  invest- 
ment with  a  napkin  over  the  finger;  cool,  remove,  trim,  and 
cement  on  the  root  with  gutta-percha  that  softens  at  a  low  heat. 

6  65 


THE  GOLD  SYSTEM. 


CHAPTER   IV. 

GOLD  COLLAK  CKOWNS. 

This  style  of  gold  crown  includes  those  methods  which  consist 
in  banding,  capping,  and  hermetically  inclosing  with  gold  the 
end  or  the  neck  of  a  root,  with  or  without  any  portion  of  a  natural 
crown,  for  the  purpose  of  securing  stability  to  the  artificial  crown, 
preventing  fracture  of  the  root  and  decay  of  the  parts,  thus  per- 
manently preserving  them.  This  method  possesses  much  practical 
value  as  a  preserver  of  tooth-structure  and  restorer  of  usefulness 
to  the  teeth,  and  affords  excellent  supports  for  bridge-work. 

Collar  crowns,  the  use  of  which  has  become  quite  general,  have 
been  described  by  many  writers  in  the  past.  Dr.  William  H. 
Dwindle  relates  the  application  of  the  method  to  a  crown  with  a 
porcelain  front,^  and  Drs.  W.  IST.  Morrison^  and  J.  B.  Beers'"' 
tell  of  it  in  the  construction  of  all-gold  cap-crowns.*  ^ 

Collar  crowns  of  which  the  part  that  essentially  constitutes  the 
cap  is  constructed  in  sections,  will  be  first  described. 

THE  CONSTRUCTION   AND   ADAPTATION    OF   COLLARS. 

Careful  study  of  the  different  f ormff  of  crowns  and  roots,  and 
of  the  anatomical  structure  and  relationship  of  the  contiguous 
parts,  is  most  essential  for  the  perfect  construction  and  adaptation 
of  collars,  bands,  or  ferrules,  as  they  are  variously  designated. 

'  American  Journal  of  Dental  Science,  April,  1855. 
^  Missouri  Dental  Journal,  May,  1869. 
'  Circular  to  dental  profession,  1873. 
*  J.  Patterson  Clark,  1836. 

^  Article  on  Writings  of  M.  Mouton,  1746,  by  Dr.  William  H.  Trueman,  Inter- 
national Dental  Journal,  October,  1897. 
66 


THE  (J()NSTRUaTI()N  AND  ADAPTATION  OF  COLLARS. 


67 


Fig.   101. 


Fig.  102. 


Many  devices  and  methods  in  use  facilitate  this  operation,  but 
its  skillful  performance  can  only  be  attained  by  study  and  practice, 
as  is  proved  by  the  easy  and  perfect  manner  in  which  it  is  done 
bv  experts  in  crown-  and  bridge-work,  who  use  no  appliances  but 
pliers  and  shears  guided  by  an  intuitive  per- 
ception of  the  requirements  of  each  case. 

The  collar  is  preferably  made  of  coin 
gold,  or  22-  to  23-carat  gold  plate.  Pure 
gold  plate  lined  with  platinum  is  also  used, 
and  platinum^  plate  in  special  cases. 

Gold  plate  of  No.  28  to  'No.  30,  or  gold 
and  platinum  about  30,  U.  S.  standard 
gauge,  affords  the  requisite  strength,  to- 
gether with  easy  adaptation  to  the  form  of 
the  crown  or  root.  The  size  of  the  cer- 
vix of  the  root  or  dimension  of  the  natural 
crown  to  be  capped,  and  whether  it  is  to 
only  effect  restoration  of  the  natural  crown 
or  to  additionally  give  support  to  bridge- 
work,  should  govern  the  choice  of  the  gauge 
of  plate  to  be  used.  Cuspids  and  molars 
require  a  heavier  plate  than  small  laterals 
or  lower  centrals,  and  in  all  forms  of  gold 
caps  the  gauge  should  be  increased  when 
they  are  to  support  bridge-work.  The 
natural  crown  or  root  having  previously 
been  properly  prepared  (see  page  35),  a 
strip  of  the  metal  is  cut  of  the  length 
i-equired,  and  generally  from  one-fourth 
to  one-half  of  an  inch  in  width  (Fig.  101). 
at  joint  is  beveled  with  a  file  (A,  Fig.  102) 


Fig.   103. 


The  end  to  underlap 
The  strip  is  then 
bent  with  suitable  pliers  (Fig.  103)  to  the  average  form  (Fig.  104), 
any  special  deviation  from  such  average  being  noted  (Fig.  105), 


*  The  use  of  platinum  plate,  62  to  34  gauge,  is  recommended  to  students,  as 
collars  formed  of  this  metal  are  not  apt  to  be  melted  in  any  of  the  soldering 
processes.  If  very  thin  platinum  is  used,  pure  gold  can  be  flowed  over  the  outer 
surface  after  it  is  adapted  to  the  cervix,  to  stiffen  it.  This  method  is  excellent 
when  a  small,  narrow  collar  is  required  for  an  incisor  crown  which  is  difficult  to 
adjust  to  the  form  of  the  root. 


68  ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 

and  to  the  size  of  the  cervical  periphery  of  the  root  of  the  tooth  to- 
be  crowned.  It  is  then  placed  on  the  root  and  adapted  as  closely 
as  possible  to  its  form,  with  the  upper  edge  of  the  metal  pressing- 

gently  under  the  free  edge 
^^^-  ^^*-  of  any  portion  of  the  gum 

it  may  meet.  It  is  then  re- 
moved and  cut  so  as  to  al- 
low the  ends  to  lap  over 
slightly.  The  adaptation 
to  the  root  is  then  con- 
tinued, during  which  pro- 
cess the  metal  should  be 
clamped  at  the  joint, 
heated,  and  chilled  in 
water  after  each  trial,  in 
order  to  maintain  the  shape 
given  to  it.  At  the  last 
adjustment  to  the  root,  the 
lap-over  is  marked  on  the 
metal  with  a  sharp-pointed 
instrument.  The  joint  i& 
made  at  this  mark  by  plac- 
ing there  the  least  possi- 
ble quantity  of  solder,  or,, 
better,  fluxed  solder  fil- 
ings, and  holding  the  collar 
with  a  clamp  in  the  flame 
of  an  alcohol  lamp  or  a 
blue  (Bunsen)  gas  flame. 
Another  method  is  to 
grasp  the  seam  of  the  col- 

The  palatal  side  of  the  superior  molars,  in   many  •.  ■■  *      1     "J  "fl 

cases,  is  of  the  large  oval  form  indicated  by  the  outer  ^^^  ^^  ^^®  CCrVlCai  Side  Wltll 

line  to  the  form  of  the  first  molar.  The  small  spurs  g^  clamp  fsce  Fio".  150)  01* 
indicate  the  points  generally  found  the  most  suitable        .  , 

to  make  the  joint.  With        COmiUOU        tweCZCrS 

held  by  pliers,  or,  better 
still,  by  a  small  hand-vise  (Fig.  106),  and  unite  the  extreme  outer 
end  of  the  seam  by  an  atom  of  solder  or  fluxed  solder  filings  with 
a  blow-pipe.  The  points  of  the  clamp  or  tweezers  prevent  the 
jBolder  from  flowing  along  the  joint.     The  cervical  side  of  the 


THE  COXSTIWC'TJON  AND  ADAPTATION  OF  COLLARS.         69 

collar  is  thus  left  open,  which  admits  of  the  collar  being  slightly 
contracted,  if  desired,  and  accurately  burnished  to  the  root.  The 
solder  can  then  be  flowed  across  the  collar  and  the  joint  closed. 
The  collar  is  then  slipped  on  the  point  of  a  small  anvil,  and  the 
joint  tapped  and  trimmed  level. 

A  method  by  measurement  is  as  follows:  The  root  is  encircled 
with  a  strip  of  thin  sheet  copper,  previously  annealed,  one-six- 
teenth of  an  inch  or  less  in  width,  and  the  copper  fitted  to  the 
■cervix.  It  is  removed,  and  cut  so  there  will  be  a  slight  lap-over 
of  the  ends  on  the  root,  then  again  fitted  to  the  root,  and  the  posi- 
tion of  the  lap-over  end  marked  on  the  copper.  This  little  strip 
of  copper,  being  soft  and  flexible,  can  be  most  accurately  fitted  to 
the  root  without  inconvenience  to  the  patient,  and  when  removed 
shows  the  exact  length  and  shape  to  cut  the  gold  or  platinum  for 
the  collar. 


Fig.   105.  Pio.   lOfi. 


Q^D 


Upon  a  strip  of  the  metal  to  form  the  collar,  from  one-quarter 
to  one-half  inch  in  width,  is  laid  the  copper  pattern,  and  the  exact 
length  required  for  the  collar  is  marked  on  the  metal,  which  is 
then  cut  a  trifle  longer  than  the  mark  indicates  (less  than  one- 
sixteenth  of  an  inch),  to  allow  for  an  over-lap  joint.  It  is  then 
bent  and  the  ends  brought  together,  the  outer  end  placed  even  or 
flush  with  the  mark,  and  soldered  as  above  described.  The  collar 
is  next  bent  to  the  shape  of  the  root,  when  it  is  ready  to  be  ad- 
justed. This  method  is  simple  and  practical,  and  also  economical^ 
as  it  accurately  defines  the  amount  of  plate  required. 

To  measure  with  a  wire:  Form  a  loop  of  copper  wire,  about  30 
gauge,  by  twisting  the  ends  together  with  pliers.  Slip  the  loop 
over  the  tooth  or  root,  press  the  wire  down  under  the  gum-margin. 


70 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


and  twist  the  ends  witk  the  pliers  until  the  loop  fits  tightly  at 
every  point  (Figs.  107  and  108).  Slip  ofi"  the  loop,  cut  it  in  the 
center  and  extend  the  ends  lengthwise  in  opposite  directions,  as 
shown  in  Fig.  109.     Then  lay  it  on  the  surface  of  the  plate  of 


Fig.   107. 


Fig.  108. 


Fig.  109. 


which  the  collar  is  to  be  constructed,  and  mark  the  length.  Cut 
the  metal  beyond  this  mark  sufficiently  to  allow  for  an  over-lap; 
bevel  and  lap  the  ends  to  the  mark  and  solder  them. 

When  a  mandrel  is  used  in  forming  a  collar,  the  size  or  shape 
is  first  taken  with  a  wire.     The  wire  ring  is  then  carefully  re- 


FiG.  110. 


Fig.  111. 


illllllllllllllllliilllll!lllllil!llllllllllllllllll|lilllll!ill!l|!|llilllllllllllllllW 


moved,  laid  on  a  piece  of  air-chamber  tin,  a  piece 

of  flat  iron  put  over  it,  and  with  a  blow  from  a 

hammer  on  the  iron  the  wire  is  driven  into  the 

tin  (Fig.  110).     The  wire  ring  is  removed  from 

the  tin,  slipped  on  a  mandreP  that  represents  the 

form  of  the  root  to  be  crowned,  and  pressed  down 

gently  as  far  as  it  will  go  without  stretching  the 

wire  (A,  Fig.  111).     The  distance  from  the  end 

of  the  mandrel  to  the  wire  is  then  measured  and 

marked    on    a    strip    of    paper,    and    the    wire 

removed.     The  gold  to  form  the  collar  is  then  bent  and  shaped 

on  the  mandrel,  with  the  edge  which  is  to  form  the  cervical  por- 

^A  description  of  mandrels  will    be  found    in  the  chapter  on  the   "Mandrel 
System  of  Bridge- Work. " 


THE  CONSTRUCTION  AND  ADAPTATION  OF  COLLARS. 


71 


tion  (B)  placed  a  little  below  the  line  of  the  wire  (A),  as  shown  by 
the  measurement  previously  taken.  The  ends  of  the  gold  are 
beveled,  slightly  lapped,  and  the  edge  of  the  lap-over  marked  (C) 
and  soldered.  The  collar  is  then  shaped  to  the  form  given  by  the 
wire  in  the  tin,  after  which  it  is  ready  for  adjustment  in  the 
mouth.  The  wire  method  of  measurement  will  be  foimd  prefer- 
able for  roots  for  collar  crowns  with  porcelain  fronts. 

Fitting  of  collar  to  root  or  tooth.  When  the  collar  has  been 
formed,  it  is  adjusted  on  the  root  and  pressed  or,  by  the  aid  of  a 
piece  of  wood,  one  end  of  which  is  placed  across  the  outer  edges  of 
the  collar,  tapped,  up  to  the  margin  of  the  gum.  A  line  parallel 
with  the  margin  is  marked  with  a  sharp-pointed  instrument  on  the 


Fig.   112. 


Fig.   113. 


Fio.   114. 


collar  (A,  Figs.  112  and 
113),  which  is  then  re- 
moved, trimmed  to  this 
mark,  readjusted,  and 
again  marked  (B),  and 
the  process  continued 
until  the  collar  fits  pro- 
portionately under  the 
margin  of  the  gum. 

If,  on  adjusting,  a  collar  is  found  a  trifle  too  small,  it  is  easily 
enlarged  by  tapping  the  gold  with  a  riveting  hammer  on  an 
anvil  (Fig.  114),  the  edge-end  of  the  collar  marked  B,  Fig.  102. 
By  this  means  the  surplus  gold  at  this  point  can  be  thrown  into 
the  collar  and  its  circumference  proportionately  enlarged  without 
altering  its  gauge.  If,  on  the  contrary,  the  collar  should  prove 
to  be  too  large  in  circumference,  the  difliculty  can  be  remedied 
by  slitting  the  gold  nearly  but  not  entirely  across  the  side  oppo- 


72 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


site  the  joint,  beveling  arid  lapping  tlie  edges  slightly,  soldering, 
and  trimming.  The  edge  is  then  burnished  to  the  periphery  of 
the  root.  For  the  purpose  of  fitting  collars  a  set  of  burnishers 
should  be  used  especially  formed  to  suit  the  different  positions 
and  avoid  irritation  of  the  margin  of  the  gum.  (See  Fig.  115.) 
Fine  serrated  foot-shaped  gold-foil  condensers  can  be  advan- 
tageously used  to  flatten  a  stiff  or  angular  point  of  a  collar. 

The  application  of  a  local  anesthetic,  such  as  cocain,  will  lessen 
the  pain  attending  the  operation.  Cocain  is  very  effective  in  tlie 
form  of  a  saturated  solution  in  glycerin.  The  parts  should  be 
surrounded  with  a  napkin,  or  with  bibulous  paper,  and  dried. 

Fig.   115. 


Then  a  drop  of  the  solution  is  placed  on  a  slab,  and'  a  little  at  a 
time  is  carried  on  the  edge  of  a  thin  burnisher  and  applied  well 
up  under  and  around  the  free  margin  of  the  gum  of  the  tooth 
operated  on.  When  this  has  been  done,  some  of  the  excess  of  the 
solution,  which  will  usually  be  found  at  the  cervix,  may  be  rubbed 
on  the  labial  and  palatal  sides  of  the  gum.  The  patient  should 
be  directed  not  to  swallow  the  saliva  during  and  for  some  time 
after  the  application  of  the  cocain.  The  anesthetic  effect  pro- 
duced by  this  method  will  usually  be  found  sufficient  to  partly 
or  entirely  divest  the  operation  of  pain,  and  of  such  duration  as 
to  seldom  require  repetition  except  at  subsequent  stages  of  the 
operation.  Electrolysis  will  effect  rapid  diffusion  of  the  cocain 
(cataphoresis),  the  solution  of  cocain  being  placed  on  cotton 
against  the  sides  and  margins  of  the  gums. 

A  weak  current  of  electricity  should  be  used,  the  positive  pole 
being  applied  to  the  cotton  and  the  negative  pole  to  the  cheek 
or  held  in  the  hand  of  the  patient. 


COLLAH    CROWNS   Ifyai/'JNKJAL/A-  CONSI DI'JiKD.  73 

COLLAR   CROWNS    HYGIENICALLY   CONSIDERED. 

The  principal  argument  against  ferruled  or  collared  crowns 
is  that  they  are  productive  of  irritation  to  the  peridental  mem- 
brane, ultimately  causing  its  absorption  and  the  exposure  of  the 
collar.  This  would  be  theoretically  and  practically  true  of  a 
rough  or  porous  substance  encircling  the  root,  or  of  an  imper- 
fectly and  unskillfully  adjusted  or  cemented  ferrule  or  collar 
which  would  by  its  presence  hold  a  position  analogous  to  a  cal- 
careous deposit,  but  no  such  comparison  can  be  fairly  made  with 
a  perfectly  fitted  collar,  forming  at  its  edge  a  smooth  and  im- 
perceptible union  with  the  sides  of  the  root,  and  presenting  a 
uniform  and  benign  surface  to  the  investing  membrane.  In  case 
of  perfectly  adapted  collars,  when  any  irritation  of  the  mem- 
brane exists,  it  will  be.  found  to  result  from  such  causes  as  usu- 
ally produce  it  when  the  natural  cro^vns  are  present,  namely, 
dental  concretions.  A  tarnished  and  unclean  condition  of  the 
surface  of  the  gold  of  the  collar  will  produce  irritation  of  the 
membranes,  which  is  a  matter  independent  of  the  collar  itself, 
and  easily  remedied  by  cleansing  and  polishing  the  surface. 
Where  an  acid  condition  of  the  secretions  of  the  mouth  exists, 
a  collar  of  platinum  or  iridium,  or  one  of  gold  and  platinum 
crown-metal,  presenting  the  platinum  surface,  is  suggested  in 
preference  to  gold,  as  these  metals  will  not  be  affected,  but  will 
constantly  present  an  untarnished  surface. 

"When  evidences  of  a  tendency  to  pyorrhea  alveolaris  exist,  a 
collar  adjusted  to  support  bridge-work  should  be  extended  well 
under  the  gum-margin,  or  the  edge  of  the  collar  kept  consider- 
ably above  it.  Where  pyorrhea  alveolaris  is  present,  a  collar  of 
fine  gold,  properly  fitted  and  extended  well  up  over  the  exposed 
section  of  the  surface  of  the  root,  has  often  a  tendency  to  retard 
the  disease,  as  calcareous  deposits  do  not  adhere  to  the  smooth 
surface  of  the  gold  so  readily  as  to  the  dentin. 


CHAPTER    V. 

GOLD  COLLAR  CROWNS  WITH  PORCELAIN  FRONTS. 

INCISORS    AND   CUSPIDS.  ' 

This  stjle  of  crown  for  incisors  and  cuspids,  as  originally  made 
by  Dr.  C  M.  Kiclimond,  and  with  which  his  name  has  become 
associated,  consisted  of  a  cap  for  the  root,  formed  of  a  band  of 
gold  capped  with  platinum  on  which  was  soldered  a  tooth  with 
a  slot  in  the  center  between  the  pins.  Through  this  slot  and  the 
center  of  the  cap  a  screw  passed  which  entered  into  a  cylinder 
previously  screwed  and  cemented  into  the  root-canal. 

The  form  of  gold  collar  crown  in  general  use  at  present  is,  in 
principle,  the  same  as  what  was  formerly  known  in  dentistry 
as  a  gold  pivot  tooth,  with  the  addition  of  a  gold  collar  for  the 
root,  and  having  the  advantage  of  oxyphosphate  for  its  cemen- 
tation. These  improvements  enhance  its  value  as  a  crown,  and 
materially  change  the  process  of  its  construction.  In  making 
an  incisor  or  cuspid  crown  of  this  style,  the  collar,  having  been 
formed,  is  trimmed  even  with  the  surface  of  the  end  of  the  root. 
With  the  collar  in  position  on  the  root,  a  corundum-wheel  is 
passed  over  the  labial  edge,  along  the  margin  of  the  gum,  to  level 
the  gold  with  the  root  and  render  it  invisible  when  the  crown  is 
finished.  The  side  of  the  wheel  should  revolve  toward  the  root, 
its  motion  even  being  reversed  for  that  purpose  when  necessary, 
the  idea  being  to  turn  the  feather-edge  of  the  metal  of  the  collar 
over  the  end  of  'the  root.  The  work  will  then  present  the  ap- 
pearance shown  in  Fig.  116. 

The  cap  is  made  by  placing  the  outer  edge  of  the  collar  against 
the  surface  of  a  piece  of  very  thin  platinum  plate  or  heavy  foil, 
adapting  the  platinum  to  the  edge  of  the  collar  and  then  uniting 
the  platinum  to  the  collar  with  solder  in  a  Bunsen  flame  (Fig. 
117).  The  quantity  of  solder  used  must  be  very  small,  barely 
sufEcient  to  unite  the  parts,  and  it  should  be  placed  on  the  plati- 
74 


GOLD  COLLAR  CROWNS   WITH  PORCPJLAJN  FRONTS. 


75 


num  outside  of  the  collar.  Used  in  that  manner  it  will  not  flow 
over  the  inside  of  the  collar  and  interfere  with  the  fit  of  the  cap. 
The  process  is  facilitated  by  first  merely  attaching  the  platinum, 
with  the  solder,  to  the  edge  of  the  collar,  then  readapting,  and 
finishing  the  soldering.  The  platinum  is  next  trimmed  to  the 
collar,  and  the  cap  adjusted  on  the  root.  The  labial  section  of 
the  surface  of  the  cap  is  then  burnished  to  the  end  of  the  root 
(A,  Fig.  116).  The  root-canal  having  been  slightly  enlarged,  a 
pin  of  round  iridio-platinum  wire,  ]S[o.  16  or  17,  U.  S.  standard 
gauge, — filed  a  little  smaller  for  laterals  or  other  roots  which 
require  it, — is  slightly  tapered  at  the  point,  fitted  to  an  aperture 
made  in  the  cap,  and  to  the  canal  (B).  The  pin  is  then  cut  off 
even  with  the  cap,  removed,  and  temporarily  laid  aside. 


Fig.  116. 


Fig.   117. 


Fig.   118. 


Fig.   119. 


A  hollow  wire,  the  open  space  in  the  center  of  which  is  very 
small,  affords  the  advantage  that  it  can  be  drilled  out  of  the 
canal  in  a  comparatively  easy  manner  if  for  any  reason  it  be- 
comes necessary  to  remove  the  crown,  as  the  drill  will  follow 
the  fine  opening  in  the  center  of  the  wire. 

To  accurately  fit  a  post  in  a  root-canal  which  for  some  reason 
has  been  reamed  considerably,  use  a  piece  of  platinum  wire  of  a 
gauge  which  will  fit  the  end  of  the  canal.  Twist  a  narrow  strip 
of  platinum  foil  on  the  post  from  the  point  downward,  and  fit 
post  and  platinum  to  the  canal.  Remove  post  and  platinum  foil 
together  and  solder  them  with  a  pellet  or  two  of  gold  foil  by  hold- 
ing in  a  Bunsen  flame. 

A  plain-plate  cross-pin  tooth,  suitable  in  form  and  color,  is 
ground  and  fitted  in  position  on  the  cap.  The  labio-cervical  edge 
of  the  porcelain  (A,  Fig.  118)  should  be  flush  with  the  edge  of 


76  ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 

the  collar,  and  meet  the  margin  of  the  gum.  It  should  be  cut 
out  at  the  base  (B)  so  as  to  form  a  slight  space  just  over  the  end 
of  the  pin.  The  tooth  is  then  backed  with  very  thin  pure  gold, 
gold  lined  with  platinum,  or  pure  platinum  foil.  Platinum  gives 
a  faint  blue  shade,  and  gold,  or  gold  lined  with  platinum,  if  the 
gold  side  is  toward  the  porcelain,  a  slight  yellow  shade.  The 
backing  should  extend  as  far  as  possible  under  and  between  the 
tooth  and  the  cap,  as  the  solder  will  flow  in  and  fill  the  space,  thus 
giving  strength  and  continuity  of  structure.  This  result  can  also 
be  effected  by  first  simply  backing  the  porcelain  with  gold  or 
platinum  and  then  shaping  a  piece  of  very  thin  platinum  foil 
to  the  base,  extending  from  A  to  B,  heating  the  porcelain,  veneer- 
ing with  a  mere  film  of  resin  and  wax,  and  by  pressure  with  a 

Fig.  120.  ,  Fm.   121.  Fig.  122. 


napkin  or  cotton  causing  the  foil  to  adhere  to  the  surface  of  the 
porcelain.  The  backing,  if  bent  over  the  incisive  edge  (C)  at  an 
obtuse  angle  to  the  line  of  the  back  of  the  tooth,  will  protect  the 
porcelain  in  occlusion.  A  narrow  strip  of  fine  gold  placed  trans- 
versely across  at  that  point  previous  to  investing,  and  united  in 
the  soldering  of  the  backing,  will  answer  the  same  purpose.  If 
the  platinum  backing  used  is  of  the  nature  of  foil,  it  is  advisable  to 
rivet  over  it  on  the  back  of  the  tooth  a  piece  of  gold  plate  smaller 
in  size,  and  in  which  a  number  of  perforations  have  been  made 
with  a  punch  forceps.  This  will  insure  against  melting  the  plati- 
num foil  off  the  porcelain  with  the  gold  solder,  which  may  occur 
if  a  pointed  flame  is  used.  The  solder  will  flow  through  the  per- 
forations and  unite  the  gold  with  the  platinum  under  it. 

The  tooth,  when  backed,  is  secured  in  position  on  the  •eap-'With 
a  compound  of  wax  and  resin,  and  the  whole  adjusted  in  the 


QOLD  COLLAR  CROWNS    WITH  ROIiCKLAIN  FRONTS.  -J J 

mouth,  then  removed,  and  the  pin,  which  has  been  laid  aside^ 
warmed  and  placed  in  position  by  passing  the  end  from  the  inside 
of  the  cap  through  the  hole  into  the  wax  attaching  the  porcelain 
crown.  Another  adjustment  in  the  mouth  is  then  made  to  deter- 
mine the  exact  line  for  the  pin,  and  the  case  is  ready  for  invest- 
ment. 

After  the  fitting  of  the  pin  to  the  root  and  root-canal,  as  was 
described  when  the  cap  was  formed,  some  prefer  to  solder  it  to 
the  cap,  for  which  purpose  it  should  be  adjusted  in  position  and 
cemented  with  wax,  then  removed,  invested,  and  soldered  (Fig. 
119).  At  this  stage  of  the  work,  if  desired,  an  impression  can 
be  taken  in  a  small  impression  cup  (Fig,  120)  with  either  plaster 
or  modelling  composition.  The  cap  should  be  removed  in  posi- 
tion in  the  impression.  An  articulation  of  the  lower  teeth  should 
also  be  obtained.  When  the  model  is  made,  the  pin  is  cut  off  even 
with  the  cap,  and  the  porcelain  tooth  fitted  as  already  described. 

Calcined  marble-dust  and  plaster,  in  the  proportion  of  two 
parts  of  marble-dust  to  one  of  plaster,  to  which  is  added  a  pinch 
of  sulfate  of  potassium  to  quicken  the  setting,  makes  what  is  con- 
sidered to  be  the  most  suitable  investing  material  for  crown-work. 
The  metallic  section  of  the  crown,  when  invested,  should  be  left 
exposed  at  the  sides,  about  as  illustrated  in  Fig.  121,  but  the 
porcelain  should  be  carefully  covered.  Pour  boiling  water  on  the 
investment  when  desirous  of  removing  the  wax  before  heating, 
but  never  attempt  to  remove  it  with  an  instrument.  Many  sim- 
ply allow  the  wax  to  burn  out.  This  is  always  done  when  fluxed 
wax  is  used.  The  investment  should  be  first  heated  over  a  Bunsen 
burner,  and  then  removed  to  a  charcoal  soldering-block.  Gold 
solder  cut  in  small  pieces  is  then  placed  in  and  over  the  aperture 
between  the  porcelain  front  and  the  cap.  By  uniformly  heating 
the  entire  investment,  especially  underneath  and  in  the  direction 
A,  with  a  large  flame  from  a  gas  blow-pipe,  the  solder  is  melted  and 
flowed  between  the  porcelain  and  cap.  More  solder  should  be 
added,  and  melted  in  this  manner  until  the  space  between  cap 
and  porcelain  is  filled  in  and  continuity  of  structure  assured; 
but  if  an  excess  is  used,  it  is  apt  to  bulge  or  flow  out  over  the 
collar.  After  letting  the  body  of  the  investment  slightly  cool, 
additional  solder  is  then  placed  on  the  backing  and  cap,  and  with 
a  small  pointed  flame  melted  and  flowed  over  these  parts.     Only 


78  ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 

sufficient  gold  should  be  used  to  insure  restoration  of  contour. 
When  soldered,  after  having  been  placed  in  acid  and  thoroughly 
divested  of  borax,  the  crown  is  ready  for  the  finishing  and  polish- 
mg  process.     Fig.  122  represents  the  completed  crown. 

When  it  is  desirable  to  protect  the  incisive  edge  of  the  porce- 
lain against  fracture  in  use  and  at  the  same  time  have  the  gold 
invisible,  the  porcelain  should  be  ground  in  the  manner  illustrated 

Fig.  123. 


A\ 


^^ 


\^ 


at  A,  Fig.  123,  The  gold  in  the  final  finishing  should  be  brought 
on  a  straight  line  to  the  edge  of  the  porcelain  as  shown  at  B. 
This  will  protect  the  edge  of  the  porcelain  in  use,  and  render  the 
gold  invisible  when  viewed  from  the  front. 

BICUSPIDS  AND  MOLARS. 

Bicuspids  crowned  by  this  method  will  have  greater  strength 
if  a  portion  of  the  palatal  section  of  the  natural  crown  is  reserved 
(Fig.  23),  and  the  band  or  collar  made  deep  enough  to  cover  it. 

The  end  of  the  root  is  capped  after  the  manner  of  the  typical 
central  already  described,  one  or  two  pins  being  used  in  the 
canals  as  required.  A  porcelain  cuspid  tooth,  or  a  bicuspid  front, 
is  then  ground,  backed,  and  adjusted  on  the  cap  to  represent  the 
labial  aspect,  and  secured  with  wax.  The  front  and  cap  are  then 
removed,  invested,  and  soldered,  after  which  they  are  adjusted 
in  the  mouth,  and  the  occluding  edge  of  the  porcelain  is  ground 


GOLD  COLLAR  (JROWNS   WITH  PORCELAIN  FRONTS. 


79 


clear  of  the  antagonizing  teeth  (A,  Fig.  124),  AVith  a  die  of 
suitable  size  representing  the  occluding  surface  of  a  bicuspid,  as 
illustrated  in  Fig.  125,  a  piece  of  pure  gold  plate  (about  JSTo.  30 
gauge)  is  swaged  (Fig.  126)  and  the  cusps  filled  in  with  18-carat 
solder  or  gold  plate. ^  The  cap  is  then  trimmed  (Fig.  127), 
ground,  and  fitted  to  the  occluding  edge  of  the  porcelain  front 
(Fig.  128)  in  proper  position  as  regards  occlusion,  and  the  wax 
attaching  it  is  shaped  to  the  contour  of  the  crown  (A).  A  piece 
of  very  thin  gold  plate  or  of  No.  60  foil  (B)  is  then  adjusted 
on  each  side  of  the  crown,  which  is  invested  (Fig.  129).  The 
long  ends  of  the  two  side-pieces  of  gold  plate  are  designed  to  retain 
theni  in  position,  as  the  investing  material  should  be  removed  from 


Fig.  124. 


Fig.   125. 


Fig.   126. 


Fig.   128. 


Fig    129. 


the  portion  inclosing  the  sides  of  the  crown  (A).  Mica — isin- 
glass— is  recommended  for  this  purpose,  and  is  preferable  to  metal. 
In  the  process  of  soldering,  the  solder  is  placed  in  the  aperture  at 
B,  and  the  flame  of  the  blow-pipe  being  directed  on  the  exposed 
sides  of  the  gold  at  A,  the  solder  is  flowed  into  every  part,  form- 
ing perfect  continuity  of  structure  of  the  metallic  portion  of  the 
crown.  If  this  aperture  at  A  is  left  open  without  the  gold  or  mica, 
and  the  solder  is  first  flowed  in  the  interstices  as  described  in 
soldering  an  incisor  crown,  the  remaining  solder  necessary  to  con- 
tour the  part  can  be  added,  if  the  pointed  flame  is  used  and  not 
applied  to  the  other  portions  of  the  crown  and  investment.  In 
finishing,  the  surplus  gold  is  trimmed  to  the  contour  of  a  bicuspid 
tooth.     Fig.  130  represents  the  finished  crown. 


1  A  hard-flowing  solder  is  be.st  for  use  in  filling  cusps  to  protect  porcelain  fronts 
to  crown-  or  bridge-work.  It  is  made  of  two  parts  18-carat  gold  plate  and  one 
part  18-carat  solder.  The  plate  and  solder  should  be  melted  together  and  rolled 
out  quite  thin  and  kept  ready  for  use. 


80 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  method  described  produces  a  perfect  and  artistically  formed 
crown,  but  simpler  and  quicker  methods  are  practiced.  One  of 
these  is  to  build  up  the  palatal  cusp  with  several  pieces  of  gold 
plate,  which  have  been  previously  melted  into  the  form  of  small 
balls  and  flattened  out  on  an  anvil.  These,  laid  in  position  and 
united  with  solder,  are  shaped  in  finishing  to  represent  the  palatal 
cusp  (Fig.  131).  The  porcelain  front  should  be  backed  so  that 
the  solder  can  be  flowed  over  its  occluding  edge. 


Fig.   ISO. 


Fig.   131. 


Fig.  132. 


Fig.  133. 


Another  method  is  to  extend  the  palatal  part  of  the  collar  down 
as  shown  in  Fig.  132,  and  then  fill  in  the  space  with  solder.  In 
finishing,  the  gold  is  trimmed  to  the  form  of  the  crown.  As 
much  as  possible  of  the  natural  crown  should  be  left  at  the  palatal 
side  of  the  collar.  The  exposed  edge  of  the  collar  may  be  slit  and 
brought  in  against  the  side  and  soldered  to  give  contour.,  With 
this  form  of  collar  one  pin,  in  the  palatal  root-canal,  is  sufficient. 
It  should  be  allowed  to  extend  out  of  the  cap  enough  to  just 
touch  the  lower  teeth  when  they  are  occluded.  The  exposed  end 
of  the  pin  will  be  an  exact  guide  in  the  soldering  as  to  the  amount 
of  solder  required  to  form  the  grinding-surface.  In  this  and  in 
the  method  just  previously  described,  the  porcelain  front  can  be 
soldered  and  the  palatal  cusp  formed  in  the  one  investment. 

The  method  of  construction  of  molar  crowns  with  porcelain 
fronts  is  similar  to  that  for  bicuspids  (Fig.  133). 

Dr.  8towelVs  Method. — A  porcelain  crown  can  be  soldered  on 
the  cap,  according  to  Dr.  S.  S.  Stowell's  method,  as  follows:^ 
"The  tooth  used  may  be  a  Logan  crown  or  an  ordinary  counter- 
sunk tooth,  but  in  most  cases  the  Logan  crown,  having  a  strong 


^Dental  Cosmos,  vol.  xxix,  page  641. 


GOLD  COLLAR  CROWNS   WITH  POIiCELAJN  FRONTS. 


81 


pin,  is  preferable.  The  pin  is  first  cut  off,  then  the  tooth  is 
ground  to  fit  on  the  cap,  the  porcelain  and  the  stump  of  the  pin 
being  reduced  alike  evenly  and  smoothly;  after  which  the  stump 
of  the  pin  is  ground  with  a  small  wheel  below  the  surface  of 
the  porcelain  (Fig.  134).  The  tooth  is  then  invested  (Fig.  135) 
and  pure  gold  fused  on  to  the  platinum  jDin,  and  while  in  a  fluid 
state  it  is  with  a  wax  spatula  'spatted'   down  flat   (Fig.    136). 


Fig.  134. 


Fig.  135. 


Fig.  136. 


Fig.  137. 


Fig.   138. 


The  gold  is  then  filed  or  ground  down  even  with  the  porcelain, 
and  at  the  palatal  border  the  tooth  is  ground  to  bevel  back  until 
the  gold  is  reached  (Fig.  137).  The  tooth  is  then  secured  in 
place  on  the  cap  with  wax  cement  (Fig.  138),  the  case  invested, 
and  heated  until  the  wax  has  melted  and  burned  out.  A  small 
clipping  of  thin  platinum  plate  is  crowded  into  the  opening  (Fig. 
139)  caused  by  the  grinding  of  the  bevel  on  the  crown.     The 


Fig.  139. 


Fig.  140. 


Fig.  141. 


Fig.  142. 


Fig.  143. 


clipping  of  platinum  serves  as  a  lead  for  the  solder,  which  fol- 
lows it  down  into  the  countersunk  cap,  around  the  ends  of  the 
dowels,  and  finally  attaches  itself  to  the  pure  gold  already  at- 
tached to  the  stump  of  the  platinum  pin.  Fig.  140  represents 
the  completed  crown.  A  sectional  view  of  a  like  crown  (Fig. 
141)  also  shows  the  organization  in  detail.  A  porcelain  crown 
can  be  used  to  represent  any  of  the  teeth  in  the  same  manner. 
(See  Figs.  142  and  143.)" 

7 


82  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

GOLD    CROWNS    WITH    PORCELAIN    FRONTS    FOR    TEETH 
WITH    LIVING    PULPS. 

In  the  anterior  teeth,  in  case  of  atrophy  or  erosion,  or  where 
decay  has  destroyed  the  approximal  sides  of  a  tooth  in  such  a 
manner  that  crowning  is  considered  the  most  desirable  opera- 
tion to  perform,  the  pulp  is  frequently  found  unexposed  and  in 
a  normal  condition.  The  importance  of  its  preservation  in  such 
a  case  is  unquestionable. 

Fig.  144.  Crowning  in  Cases  of  Abrasion. — In  a  case  of  ex- 
tensive abrasion  of  the  incisive  edges  of  the  anterior 
teeth,  with  pulp  living  though  considerably  calcified 
in  the  coronal  section,  crown-work  to  restore  the 
length  and  form  of  the  teeth  is  best  performed  by 
removing  a  portion  of  the  labial  aspect  of  the  natural 
crown  and  then  forming  the  artificial  crown  similar 
to  a  gold  collar  crown  with  a  porcelain  front  with- 
out the  pin.  Fig.  144  gives  an  outline  of  the  con- 
struction of  such  a  crown.  If  a  case  should  suggest 
the  necessity  of  a  pin,  a  short  one  can  be  so  inserted  between 
the  line  of  the  pulp-chamber  and  the  palatal  wall. 


CHAPTER    VI. 

ALL-GOLD  COLL  All  CKOWNS  FOK  BICUSPIDS  AND  MOLARS 
CONSTRUCTED  IN  SECTIONS. 

The  root  and  crown  having  been  properly  prepared,  the  collar 
is  formed  and  adjusted  as  described  at  page  71,  and  the  edge 
toward  the  antagonizing  teeth  trimmed,  to  fully  clear  them  in 
occlusion.  The  collar  is  then  slightly  expanded  toward  the  oc- 
cluding surface  for  better  contour.  A  close  knuckling  can  be 
insured  by  seizing  the  collar  and  the  approximal  tooth  in  the  man- 
ner shown  in  Fig.  145.  The  collar  is  removed,  filled  with  plaster, 
and  adjusted  in  position.     Fig.   146   represents  a  typical  case. 


Fig.  145. 


Fig.  146. 


The  antagonizing  teeth,  having  been  covered  with  a  piece  of  tin 
foil,  are  then  occluded  until  the  plaster  sets.  The  collar  is  then 
removed.  The  surface  of  the  plaster  inside  the  collar  will  give 
the  impression  of  the  natural  root  or  crown,  and  the  outside  that 
of  the  antagonizing  teeth.  The  latter  furnishes  an  outline  to 
form  the  grinding-surf ace  of  the  crown. 

The  plaster  is  then  trimmed  and  shaped  to  represent  the  cusps 
and  fissures  of  the  natural  tooth,  enough  of  the  surface  being 
removed  to  allow  for  the  thickness  of  the  plate  that  forms  the 
cap. 

A  small  tube  of  copper,  a  trifle  larger  in  circumference  than 
the  crown  under  construction,  is  filled  with  Melotte's  "moldine," 
and  the  surface  rubbed  with  soapstone.     An  impression  of  the 

83 


84 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


lower  portion  of  the  form  of  the  crown  A  to  the  line  B,  Fig.  147, 
is  then  made  in  the  moldine,  and  a  strip  of  paper  wound  around 


Fig.   147. 


Fig.  148. 


the  tube,  extending  about  an  inch 
above  the  edge. 


Fusible  alloy  is 
then  melted  and  poured  into  the 
mold,  thus  forming  a  die.  An  in- 
dentation is  made  with  a  punch  in  a 
block  of  lead,  into  which  the  die, 
when  cold,  is  hammered  slightly 
beyond  the  impression  of  the  edge 
of  the  collar.  By  this  method 
a  die  and  a  counter-die  (Fig.  148) 
can,  with  practice,  be  completed 
in  five  minutes.  With  this  die 
the  cap  is  then  struck  up  on  the 
lead  from  a  flat  piece  of  plate 
and  fitted  to  the  collar.  A  little 
of  the  surface  of  the  plaster  in  the  collar  may  have  to  be  re- 
moved, if,  on  trial  in  the  mouth,  the  cap  is  found  a  little  flush. 
The  crown,  with  the  plaster  still  inside  the  collar,  is  fixed  in  a 
soldering-clamp  constructed  in  one  of  the  forms  shown  in  Figs. 
149,  150,  and  151,  which  holds  the  parts  together  and  permits  the 


A,  Fusible  die. 

B,  Counter-die. 

C,  Plate    to    form 
the  cap. 


Fig.  149. 


Fig.  150. 


The  frame  of  this  clamp  is  formed  of  iron  wire,  and  the 
support  for  the  crown  of  plaster,  asbestos,  and  marble-dust. 


flame  to  reach  all  points.  "With  the  clamp  Fig.  149,  the  blow-pipe 
flame  is  the  best.  The  other  forms  suggest  the  Bunsen  flame. 
The  parts  of  the  crown  can  also  be  held  together  for  soldering  with 
iron  wire  in  the  form  of  a  loop  passed  over  the  grinding-surface, 
against  the  sides  of  the  collar,  with  the  ends  twisted  together  over 


ALL-GOLD  COLLAR  CROWNS  CONSTRUCTED  L\  SECTIONS,    go 


the  aperture  of  the  neck  of  the  crown.  ISTo  more  solder  should 
be  used  than  the  contour  requires,  as  an  excess  necessitates  addi- 
tional labor  in  finishing.  y^q    151 

Another  method,  if  the  crown  is  not 
to  be  contoured  with  the  aid  of  the  sol- 
der, is,  when  the  cap  is  struck  up,  to 
melt  solder  into  the  cusps,  and  then 
adjust  the  cap  in  jDosition  on  the  collar, 
for  which  purpose  some  of  the  plaster 
underneath  the  cap  must  be  removed. 
A  jet  of  flame  from  the  blow-pipe  is 
then  thrown  upon  it  in  such  a  way  as- 
to  cause  the  solder  to  flow  down  on  the 
edge  of  the  collar  and  fill  the  seam  from 
the  inside.  The  objection  to  this  method 
is  that,  when  a  large  portion  of  the 
natural  crown  is  inclosed  by  the  gold, 
the  solder  will  occasionally  alter  the 
inside  form  of  the  fitted  cap,  thereby 
interfering  with  its  adjustment,  which 
is  a  defect  troublesome  to  correct. 

Still  another  method  specially  suita- 
ble in  cases  where  all  or  nearly  all  of 
the  grinding-surface  of  the  natural 
crown  is  present  or  where  the  bite  is 
close,  is  to  adjust  the  collar  in  the  mouth, 
and,  with  a  small  piece  of  wax  or  im- 
pression-compound pressed  upon  it,  to 
take  an  impression  and  ''bite,"  in  which 
the  collar  will  be  imbedded  and  re- 
moved. With  this  a  model  and  articu- 
lation are  made  and  the  form  of  the  cap 
shaped  in  wax.  An  impression  of  the 
cap  is  then  made,  either  in  moldine  in 
a  soft  state  in  a  tube,  or  in  plaster,  and 
a  die  cast.  The  cap  is  stamped  on  this 
die,  then  adapted  to  the  collar  by  the 
model,  and  the  crown  finished.  This  method,  which  was  first 
made  known  by  Dr.  IST.  W.  Kingsley,  can  be  adopted  when  it  is 


86 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


preferable  to  construct  the  crown  between  the  visits  of  the  pa- 
tient after  having  first  made  and  fitted  the  collar. 

In  utilizing  a  tooth  as  an  abutment  in  bridge-work  when  all 
or  nearly  all  of  the  occluding  surface  of  the  natural  crown  is 
present,  a  practical  method  of  construction  is  to  mark  the  out- 
line of  the  natural  crown  on  the  inner  surface  of  the  collar; 
then  remove  the  collar  and  trim  so  as  to  leave  a  border  of  about 
one-sixteenth  of  an  inch  outside  the  mark.  This  border  is  then 
thinned  with  a  corundum-wheel,  and  slit  as  seen  in  Fig.   152. 


Fig.  152. 


Fig.   153. 


Fig.  154. 


The  collar  is  next  adjusted  on  the  natural  crown,  and  the  slit  bor- 
der bent  over  to  the  form  of  the  occluding  surface,  to  which  it  is 
burnished.  A  piece  of  pure  gold  plate,  about  ISTo.  34  gauge,  is 
then  placed  on  the  occluding  surface  of  the  tooth  and  adapted  to 
it  and  to  the  collar.  The  gold  may  be  first  struck  in  the  form 
of  a  cap  by  laying  it  on  a  block  of  lead  and  hammering  into  it 
a  die  of  the  surface  of  the  tooth  to  be  crowned  (Fig.  153),  or  one 
corresponding  closely  to  it.  The  antagonizing  teeth  are  then  oc- 
cluded on  the  gold,  which  is  thereby  pressed  to  form  to  articulate 
with  the  occluding  surfaces.  Enough  of  the  occluding  surface  of 
the  tooth  crowned  should  always  be  removed  to  allow  for  the 
thickness  of  the  gold  covering  its  surface.  The  collar  and  cap  are 
next  removed  and  soldered.  This  is  done  by  resting  the  collar 
on  the  cap,  which  is  held  by  a  pair  of  tweezers,  or  by  clamping 


ALL-GOLD  COLLAR  CROWNS  CONSTRUCTED  IN  SECTIONS.    87 

the  cap  and  collar  together  and  placing  the  solder  in  small  pieces 
around  the  collar  outside  the  cap,  at  A,  Fig.  154,  and  soldering 
by  holding  in  a  blue  gas  flame.  Only  sufficient  solder  should 
be  used  to  join  and  fill  the  seams,  so  that  it  will  not  interfere 
with  adjustment  on  the  natural  crown.  A  closer  and  neater  joint 
will  be  obtained  by  at  first  attaching  only  one  corner  of  the 
crown  to  the  collar,  with  the  smallest  possible  quantity  of  solder, 

Fio.  155. 


UPPER 


LOWER 


then  readjusting  collar  and  cap  on  the  tooth,  adapting  their  edges 
together  with  a  foot-shaped  foil  condenser,  and  then  completing 
the  soldering. 

The  methods  described  insure  a  perfect  occlusion  of  the  crown 
with  the  antagonizing  teeth.  In  the  absence  of  antagonizing 
teeth,  or  when  the  general  form  of  the  grinding-surface  permits 
it,  the  cap  can  be  struck  up  with  a  die  similar  to  the  one  shown 
in  Fig.  153  that  approximates  in  size  and  form  what  is  required. 
The  cusps  are  then  filled  in,  and  the  edges  of  the  inner  surface  of 
the  cap  ground  level  on  the  side  of  a  corundum-wheel.  The  en- 
tire circumference  of  the  edge  of  the  collar  is  also  leveled,  and 


88 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


the  cap  adjusted,  clamped,  and  soldered.  If  the  cusps  of  the  cap 
are  filled  in  with  solder,  it  will  flow  down  and  join  the  collar  on 
the  inside;  if  with  gold  plate,  the  cap  and  collar  must  be  joined 
with  solder  either  on  the  inside  or  outside. 


Fig.  156. 


Fig.   157. 


When  the  mere  form  of  the  grinding-surface  for  the  crown 
is  all  that  is  required,  an  impromptu  one  may  be  made  by  in- 
denting a  piece  of  pure  or  soft  gold  plate  mth  the  round  end  of 
an  instrument-handle  on  a  piece  of  lead  to  form  the  cusps,  then 

reversing  the  cap,  resting  it  on  a 
flat  surface,  and  creasing  be- 
tween the  cusps  with  a  bur- 
nisher. 

Metallic  caps,  or  forms  of  the 
occluding  surfaces  of  teeth  for 
use  in  constructing  crowns,  are 
quickly  made  with  the  die-plate 
shown  in  Tig.  15  5,^  "in  which 
are  four  groups  of  intaglio  dies 
representing  the  peculiar  cusps 
of  the  bicuspids  and  molars.  The  hubs  A,  B  (Fig.  156)  are  of  the 
sizes  shown,  and  are  made  of  an  alloy  composed  of  tin  one  part, 
lead  four  parts,  melted  together.     The  mold  0  should  be  warmed! 


^  Dental  Cosmos,  vol.  xxix,  page  482, 


ALL-(,'()LI)  COf.L.lU  CROWNS  CONSTRUCTED  IN  SECTIONS.    89 

the  metal  alloy  poured  in  every  hole,  and  the  overflow  wiped  off 
just  before  the  metal  stiffens;  this  will  make  the  butts  of  the  hubs 
smooth  and  flat.  After  a  minute  or  two  the  mold  may  be  reversed, 
the  hubs  shaken  out,  and  the  casting  process  continued  until  a 
considerable  number  of  hubs  sliall  have  been  made.  In  Fig.  157 
a  molar  hub  is  shown  in  place  on  a  piece  of  ISTo.  32  gold  plate, 
which  lies  over  the  upper  right  first  molar  die.  A  succession  of 
blows  on  the  hub  witli  a  four-pound  smooth-faced  hammer  will 
drive  the  plate  into  the  die,  and  at  the  same  time  spread  the  hub 
metal  from  the  die  center  to  its  circumference,  in  such  a  manner 


Fig.  158. 


that  the  plate  will  be  perfectly  struck  up  with  the  least  possible 
risk  of  being  cracked.  The  flattened  hub  is  seen  in  Fig.  158, 
which  also  shows  at  D  the  obverse  of  the  struck-np  hub,  and  at  E 
the  cameo  of  the  struck-up  plate,  having  every  cusp  and  depres- 
sion sharply  defined.  The  counter-die  plate  (Fig.  155)  is  made 
of  a  very  hard  cast  metal,  which  will  admit  of  the  striking  np  of 
many  crown  plates  by  the  means  described,  if  the  crown  plates 
be  not  too  thick  and  stiff.  Of  course  they  should  be  annealed  be- 
fore they  are  placed  over  the  die.  If  a  cusp  or  fissure  should 
chance  to  crack  in  hubbing,  a  small  piece  of  plate  may  be  struck 
up  over  the  fissure,  and  then  soldered  to  the  original  cap." 

The  methods  which  have  been  described  for  the  construction  of 
all-gold  bicuspid  and  molar  crowns  are  those  generally  adopted 
in  practice.     Of  others.  Dr.  J.  J.  R.  Patrick's  method^  consists 

1  Dr.  Patrick's  crown-work  methods  and  the  principles  upon  which  they  are 
hased  are  set  forth  in  a  paper  published  in  the  Dental  Cosmos  for  October,  1888, 
page  706. 


90  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

of  first  forming  a  very  narrow  collar  and  telescoping  it  witli  a 
seamless  cap  of  the  form  of  the  crown,  and  soldering  along  the 
line  of  the  cap  to  the  collar. 

A  method  of  making  a  gold  crown  by  stamping  it  out  of  one 
piece  of  gold  plate  is,  make  or  select  a  metallic  die  for  the  crown 
to  be  formed;  then  place  a  piece  of  pure  gold  plate,  about  JSTo.  31 
gauge,  on  the  flat  surface  of  a  block  of  lead,  and  gradually  stamp 
the  die  downward  into  the  gold  to  about  half  the  depth  of  the  in- 
tended crown.  The  gold  is  then  removed,  and  each  side  of  the  un- 
swaged  portion  slit  and  adapted  to  the  form  of  the  die,  the  full 
length  of  the  crown,  which  is  then  adjusted  in  the  mouth,  the 
edges  of  the  gold  trimmed  to  the  proper  form,  and  the  slits  sol- 
dered. 

Dr.  M.  Rynear's  crown  is  of  the  same  general  character  and 
construction  as  the  one  just  described,  except  that  a  seamless  cap 
is  used  to  form  the  crown,  instead  of  a  flat  piece  of  plate. 

All-Gold  Crowns  for  the  Incisors  and  Cuspids. — When  the 
teeth  are  abraded  or  short  and  the  incisive  edges  flat,  and  the  all- 
gold  crown  required  is  to  correspond  in  form  or  be  only  a  little 
longer,  the  gold  collar,  after  being  fitted  to  the  tooth,  is  slit  on 
the  palatal  or  lingual  side,  and  bent  and  burnished  to  it.  The 
collar  is  then  removed  and  the  seams  soldered  together.  This 
is  best  done  by  holding  the  collar  in  a  Bunsen  gas 
Fig.  159.    fl^me,  with  the  solder  placed  in  position  in  very  small 

a  pieces,  and  only  sufficient  in  quantity  to  join  the  seams. 
The  collar  is  next  adjusted  to  the  tooth,  and  the  gold 
at  the  incisive  edge  trimmed  even.  A  flat,  thick  piece 
of  gold  plate  or  clasp-material  is  soldered  across  the 
incisive  edge  to  form  and  inclose  that  portion  of  the  crown. 

When  the  crown  required  is  of  the  normal  form,  the  collar 
when  properly  fitted  should  be  removed  at  the  palatal  section, 
as  shown  in  Fig.  159.  The  edge  of  the  gold  is  then  chamfered, 
and  bent  and  burnished  over  the  incisive  edge  and  sides,  close  tO' 
the  natural  tooth.  To  this  open  section  is  next  adapted  a  flat 
piece  of  gold  plate,  the  collar  is  removed,  and  the  parts  are  sol- 
dered together,  using  very  little  solder.  Fluxed  solder  filings  can 
be  melted  in  the  interior  of  the  incisive  edge  to  increase  its  thick- 
ness. 


160. 


ALL-GOLD  COL  LA  It  CROWNS  CONSTRUCTED  IN  SECTIONS.    91 

Another  method  is  to  select  a  porcelain  tooth  of  the  desired 
form  and  of  the  size  of  the  gold  crown,  and  use  it  as  a  model  to  cast 
an  intaglio  die.  The  die  is  made  by  placing  moldine  in  a  pill 
box,  smoothing  off  the  surface,  and  imbedding  half  of  the  por- 
celain tooth  with  the  palatal  or  pin  side  down.  Kext  wind  some 
paper  around  the  box,  slightly  warm  the  porcelain  tooth,  and  pour 
in  fusible  metal.  On  this  intaglio  die  shape  a  piece  of 
gold  plate,  30  to  32  gauge,  to  the  form  of  the  labial  sur- 
face of  the  crown.  Kemove  and  bend  the  metal  round 
to  the  form  of  the  sides  and  palatal  section  of  the  tooth, 
trim  the  meeting  edges,  and  solder.     (Fig.  160.)^ 

A  fusible  metal  die  of  the  prepared  form  of  the  natural  tooth 
is  a  material  aid  in  the  construction  of  this  style  of  crown. 

In  pulpless  teeth  with  only  a  little  or  none  of  the  natural  crown 
remaining,  the  root  can  be  shaped  and  capped  as  for  a  collar 
crown  with  a  porcelain  front  (see  Chapter  V),  using  a  gold  front 
instead  of  the  porcelain.  This  can  be  made  by  shaping  or  stamp- 
ing the  form  of  the  labial  face  of  the  tooth  required  in  gold  plate, 
mounting  it  in  position  on  the  cap  as  in  the  case  of  a  porcelain 
front,  and  attaching  with  solder.  The  concave  portion  at  the 
palatal  side  of  the  gold  front  is  filled  in  and  shaped  at  the  same 
time. 

Fig.  161. 


To  correct  the  accidental  presence  of  solder  on  the  inside  of  a 
crown,  which  interferes  with  its  adjustment,  make  a  thin  paste  of 
1  Dr.  J.  T.  Usher,  Dental  Cosmos,  vol.  xl. 


92 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


rouge  and  oil.  To  determine  exactly  at  wliat  point  the  gold 
strikes,  paint  the  natural  tooth  with  the  paste  and  place  the  crown 
upon  it.  The  interfering  spot  will  be  exactly  marked  on  the 
gold.  This  should  be  trimmed,  and  the  crown  again  inserted  to 
determine  whether  enough  has  been  removed.  If  preferred  the 
paste  can  be  placed  on  the  inside  of  the  gold  crown,  when  the  in- 
terfering point  will  be  marked  on  the  natural  tooth,  which  can 
then  be  trimmed  instead  of  the  gold  to  permit  proper  adjustment. 

Pig.  162. 


Fig.  161  represents  a  case  of  abrasion  of  the  lower  teeth,  to 
Avhich  all-gold  crowns  have  been  applied,  as  shown  in  Fig.  162. 
In  such  cases,  owing  to  the  attrition  of  the  occluding  teeth,  the 
cap  forming  the  occluding  surface  should  be  constructed  of  heavy 
gold  and  platinum  plate.  An  artificial  plate  replaces  the  upper 
teeth. 


CHAPTEK    VII. 


THE   GOLD   SEAMLESS   CAP-CROWN. 


This  method  consists  in  the  use  of  a  gold  seamless  cap  for  the 
construction  of  the  required  root  cap  or  crown. 

INCISORS,    CUSPIDS,   AND    BICUSPIDS,   WITH    PORCELAIN 

FRONTS. 

Incisor,  cuspid,  and  bicuspid  crowns  with  porcelain  fronts  are 
constructed  by  this  method  as  follows:  The  natural  crown  is 
ground  down  to  within  about  one-eighth  of  an  inch  of  the  gum 
at  the  palatal  wall,  or  enough  to  clear  the  antagonizing  teeth  when 
occluded,  and  slanting  from  the  posterior  edge  of  the  pulp-cham- 
ber to  the  cervico-labial  edge  of  the  gum  and  slightly  under  its 
margin  if  it  is  desirable  to  conceal  the  joining  of  the  crown  with 
the  root.  The  sides  are  shaped  the  same  as  for  a  collar  crown 
(Fig.  163).  A  die  of  the  end  of  the  root  is  then  made.  For  this 
purpose  an  impression  of  the  part  is  taken  with  gutta-percha  on 
the  end  of  a  piece  of  wood  trimmed  to  the 
proper  size,  or,  better  still,  by  placing  some 
plaster  of  Paris  with  a  little  sulfate  of  potas- 
sium, mixed  to  the  consistence  of  a  paste,  in 
a  tube  formed  of  a  strip  of  copper  about  one 
and  one-half  inches  in  length  and  three- 
eighths  of  an  inch  in  diameter,  cut  out  on  the 
sides  to  the  depth  of  half  an  inch,  with  the 
flange  for  the  palatal  side  shortened^  (^ig- 
164).  The  impression  thus  taken  will  be  con- 
fined almost  entirely  to  the  end  of  the  root  to 
be  capped.  When  gutta-percha  is  used,  it  is  cooled  and  dried  per- 
fectly. A  strip  of  paper  is  tied  around  the  wood  or  tube,  and  a 
die  cast  with  the  fusible  metal.     The  cooling  is  hastened  by  im- 


FiG.  163. 


Fig.  164. 


^  See  article  on  "  Molds  and  Dies, 
.soldering. 


which  describes  how  to  make  a  tube  without 


93 


94 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


mersion  in  a  glass  of  water.  When  cool,  the  die  is  removed  from 
the  mold,  and  the  metal  is  trimmed,  with  file  and  chisel,  a  little 
deeper  than  the  gum  has  permitted  the  impression  of  the  root  to 
be  taken,  and  without  altering  the  form  of  the  end  of  the  root 
(Fig.  165).  A  counter-die  is  then  made  bj  punching  a  hole  in 
the  surface  of  a  block  of  pure  lead,  and  with  a  few  blows  of  a 
hammer  driving  the  die  into  it. 

A  cap  of  pure  gold,  or  preferably  of  platinum,  can  be  formed 
by  x^lacing  a  piece  of  the  plate,  J^o.  30  gauge,  of  suitable  size  upon 


Fig.  165. 


Fig.  166. 


Fig.  168. 


Fig.  167. 


a  block  of  lead,  and  with  an  oval-shaped  punch  one-fourth  of  an 
inch  in  diameter  gradually  driving  it  into  the  lead  until  the  gold 
has  assumed  the  shape  of  a  cap  about  a  quarter-inch  in  depth  (A, 
Fig.  165).  The  gold  should  be  withdrawn  from  under  the  punch 
and  annealed  several  times  during  the  process.  Caps  can  also  be 
made  with  a  stamping-press.      (See  page  101.) 

The  cap  is  then  annealed  and  swaged  on  the  die  to  the  form 
of  the  end  of  the  root  (B,  Fig.  165).  The  palatal  portion  of  the 
cap  should  be  allowed  to  go  well  up  under  the  free  edge  of  the 
gum,  and  at  the  cervico-labial  edge  it  can  be,  if  preferred,  cut 
out  to  the  edge  of  the  root.  In  the  process  of  adjustment,  the 
edges  which  fit  under  the  gum  should  be  marked  and  trimmed  as 
directed  in  describing  the  construction  of  a  collar  crown,  and 


THE  GOLD  SEAMLESS  (JAP-CROWN.  95 

then  burnished  close  to  the  sides  of  the  root  and  into  the  orifice 
of  the  root-canal,  forming  a  perfect-fitting  seamless  cap  (Fig. 
166).  An  iridio-platinum  pin  is  then  fitted  in  the  root-canal  and 
soldered  to  the  cap  (Fig.  167),  or  afterward  adjusted  as  in  the 
construction  of  the  gold  collar  crown  with  porcelain  front  (page 
75),  with  which  operation  the  remainder  of  the  process  of  con- 
struction is  identical.     Fig.  168  represents  the  completed  crown. 

The  advantages  of  this  style  of  crown  are,  simplicity,  as  the 
formation  of  a  collar  is  avoided,  and  strength,  as  a  large  portion 
of  the  natural  crown  can  be  left  at  the  palatal  side.  This  affords 
a  stronger  and  more  reliable  foundation  than  can  be  obtained  at 
any  other  point,  as  the  direction  of  the  force  in  mastication  is 
forward  at  an  angle  with  the  line  of  the  root,  and  although  the 
gold  of  the  cap,  where  it  encircles  the  root  at  the  cervico-labial 
edge,  is  entirely  removed,  the  crown  is  still  held  securely. 

In  a  paper  on  the  subject  of  preserving  and  utilizing  this 
part  of  the  tooth,  Dr.  W,  F.  Litch,  of  Philadelphia,  describes  a 
crowning  operation,^  in  which  he  constructed  the  cap  of  platinum 
by  slitting  a  piece  of  the  plate  in  a  number  of  places,  adapting  it 
to  the  end  of  the  root,  and  then  soldering  the  whole  together. 

This  operation  is  not,  however,  so  easily  or  so  satisfactorily 
performed  as  the  method  above  described.  In  some  respects  pure 
platinum  is  preferable  to  gold  in  capping  roots,  as  it  is  less  likely 
to  be  affected  by  the  secretions  of  the  mouth. 

ALL-GOLD  SEAMLESS   BICUSPIDS    AND  MOLARS. 

All-gold  seamless  crowns  for  bicuspids  and  molars  that  will 
accurately  fit  the  natural  crown  and  root,  and  occlude  properly 
with  the  antagonizing  teeth,  are  easily  and  quickly  formed,  if 
sufiicient  of  the  natural  crown  remains  to  admit  of  temporary 
restoration  of  its  contour  with  gutta-percha  or  any  other  suitable 
plastic  material.  The  sides  of  the  natural  tooth  should  be  re- 
moved at  least  the  thickness  of  the  plate  to  be  used.  An  im- 
pression of  the  restored  tooth  is  then  taken  in  plaster  or  gutta- 
percha in  a  tube,  as  explained  on  page  93,  and  a  die  then  formed 
of  fusible  alloy;  or  a  plaster  model  can  be  made  from  an  impres- 
sion of  the  tooth  taken  in  wax,  and  a  mold  obtained  from  the 
model  with  moldine.  Additional  preparation  and  shaping  of  the 
^Dental  Cosmos,  vol.  xxv,  No.  9,  page  449. 


96 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


natural  crown  to  receive  the  artificial  crown  can  then  be  proceeded 
with. 

Where  the  natural  crown  is  very  badly  decayed  or  broken 
down  and  the  method  just  described  is  not  practicable,  the  por- 
tion of  the  natural  crown  or  root  remaining  should  be  shaped 
and  prepared  to  receive  an  artificial  crown.  Then  the  form  of 
the  cervix  is  ascertained  with  a  wire  as  described  on  page  69, 
an  impression  of  the  parts  taken  in  wax  or  impression  compound, 
and  the  wire  form,  the  twisted  ends  having  been  shortened,  is 
carefully  adjusted  on  the  wax  at  the  cervical  line.  The  plaster 
model,  when  made,  will  show  the  wire  slightly  imbedded  in  the 
plaster.  The  plaster  should  be  trimmed  to  the  inner  edge  of  the 
wire,  as  that  represents  the  exact  form  of  the  root  (Fig.  169). 


Tig.  169. 


Fig.  170. 


Another  method  is  to  fit  a  copper  collar  accurately  to  the  root, 
removing  it  in  the  impression.  In  such  a  case  plaster  ought  to  be 
used.  When  the  model  is  made  the  collar,  on  being  cut  and  re- 
moved, will  present  the  exact  form  of  the  neck. 

From  a  "bite"  taken  in  wax  a  plaster  articulation  is  then 
made  to  the  model.  A  hole  is  drilled  in  the  center  of  the  form 
of  the  root  on  the  model  to  be  crowned.  In  this  hole,  and  over 
the  end  of  the  root,  a  ball  of  soft  plaster,  slightly  colored  with 
carmine,  is  placed,  and  the  teeth  of  the  articulation,  covered  with 
tin  foil,  closed  on  it.  This,  on  separation,  gives  the  outline  of  the 
form  of  the  grinding-surface  for  the  crown.  The  sides  of  the 
plaster  are  then  trimmed  to  the  form  of  the  crown,  and  the  whole 
carved  in  detail  (Fig.  170).  As  the  crown  will  always  stamp 
larger  in  circumference  than  the  die,  in  proportion  to  the  thick- 
ness of  the  gold  used,  an  allowance  must  be  made  by  trimming 


THK  GOfJJ  SK.IM/J:ss  CI /'-Ch'DU.W 


97 


off  a  proportionate  amount  of  the  grinding-surface.  When  the 
plaster  model  for  the  crown  is  made,  it  is  separated  from  the  rest 
of  the  model  at  the  dotted  line  seen  in  Fig.  170,  and  trimmed  in 
the  form  shown  hy  the  cast  A,  Fig.  171.  From  this  model  the  die 
is  made  in  a  tuLe  with  nioldine  and  fusible  metal  as  described  at 
page  84.  Tlie  cast  should  always  be  lengthened  at  the  neck,  so 
that  the  crown  when  constructed  shall  have  a  sui-plus  in  depth  of 
gold  to  allow  for  any  trimming  or  shaping  of  the  collar  that  may 
be  required.  The  counter-die  (B,  Fig.  171)  is  made  by  punching 
a  hole  in  a  block  of  lead  and  hammering  the  die  into  it.  The 
crown,  which  is  usually  formed  of  pure  gold,  or  gold  slightly  al- 
loyed, or  gold  lined  with  very  thin  platinum  from  Xo.  30  to  iSTo. 
32  gauge,  is  then  made  by  first  stamping  a  piece  of  plate  (see  page 


Fig.  171. 


Fig.  173. 


Fig.  174. 


00 J  ill  the  form  of  a  cap  of  gold  (A,  Fig.  172). 
The  cap  is  then  placed  on  the  cast,  and  mth  the  aid 
of  the  counter-die  (B,  Fig.  171)  swaged  to  the  form  of  the  crown 
B,  Fig,  172.  A  piece  of  kid-leather  or  rubber  dam  should  be 
used  to  cover  and  protect  the  gold  from  the  lead,  and  to  facilitate 
its  removal  from  the  counter-die.  An  allowance  for  the  thickness 
of  the  leather  must  be  first  made,  by  driving  it.  without  the  gold 
on  the  cast,  into  the  counter-die  to  enlarge  it.  If  this  is  not  done, 
the  gold  is  liable  to  be  torn  in  the  swaging. 

Dr.  C.  B.  Parker's  method  of  stamping  the  piece  of  gold  plate 
is  to  form  two  dies  of  the  required  crown, — the  first  with  a  cone- 
shaped  neck  up  to  the  grinding-surface  (Fig.  1T3),  and  the  second 
straight  on  the  sides  (Fig.  174).  The  gold  is  stamped  up  on  the 
first  die,  giving  the  grinding-surface,  liut  leaving  tlie  sides  flaring, 
and  then  on  the  second  to  straighten  the  sides. 


98 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Cuspid  cro^vns  from  whicli  a  portion  of  the  gold  on  the  labial 
aspect  is  to  be  removed,  or  which  are  to  be  used  entire  as  a  sup- 
port for  bridge-work,  can  usually  be  advantageously  formed  with 


Fra.   175. 


a  seamless  cap  (Fig.  175).  The  necks  of  these  crowns  can  be  con- 
tracted in  fitting  in  a  contracting  plate,  or  slit,  lapped,  and  sol- 
dered, should  the  case  so  require.  (For  details  of  process  of  ad- 
justment and  insertion,  see  "Adjustment  of  Seamless  Contour 
Crowns,"  page  102.) 


^ 


CHAPTEEVIII. 

GOLD  .SEAMLESS  CONT<JUK  CIlOWNS.i 

The  artistic  requirement  in  all-gold  crown-work  is,  that  it  shall 
reproduce  the  anatomical  contour  of  the  natural  teeth.  This  is 
usually  accomplished  by  melting  solder  on  the  collar  and  then 
trimming  it  to  the  form  of  the  crown.  A  preferable  method  is 
to  shape  the  metal  forming  the  sides  of  the  crown  by  swaging. 
This  is  easily  done  in  a  crown  formed  in  sections,  but  a  special 
process  is  required  in  the  construction  of  seamless  crowns. 

A  contour  crown  can  be  made  by  placing  a  seamless  cap  on  a 
sectional  die  or. mandrel  of  the  shape  of  the  tooth,  first  swaging 


Fio.  176. 


Fia.  177. 


Fig.  178. 


the  grinding-surf ace  on  the  mandrel  and  then  stamping  downward 
on  the  straight  sides  of  the  crown  with  a  cap  fitted  to  the  shank 
part  of  the  mandrel.  But  such  a  process,  like  many  others,  is 
too  complicated  to  be  of  any  use  to  the  dental  practitioner.  The 
sectional  mold  method  here  presented  is  simple,  practical,  and 
general  in  its  application. 

To  describe  and  illustrate  the  process,  we  will  take  one  of  the 
most  dijfficult  crowns  to  construct, — a  superior  molar  (Fig.  176). 
A  natural  tooth,  or  one  made  of  plaster,  is  used  as  a  model.  From 
this  a  sectional  mold  is  made,  as  illustrated  in  Figs.  177  and  178, 

^  Gold  crowns  of  this  form  are  now  made  and  sold  as  the  "Evans  Gold  Crowns." 
The  Evans  Gold  Non-fusible  Crown  is  lined  with  platinum  on  the  interior  of  the 
<:K;cluding  surface  and  part  of  the  sides,  to  prevent  melting  the  gold  in  soldering. 

99 


100 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


in  Babbitt's  metal,  zinc,  or  fusible  alloy.  Into  tlie  mold  a  cap  of 
gold  (Fig.  1Y9)  23  to  24  carats  fine,  Jn'o.  28  to  30  gauge,  is  ad- 
justed, fitting  tightly  the  orifice  of  the  closed  mold.  The  mold 
is  placed  in  a  vise,  the  cap  expanded  to  the  general  form  of  the 
mold  by  hammering  it  into  a  mass  of  cotton,  and  then  swaged  more 
in  detail  to  the  form,  and  with  a  wood  point  or  a  burnisher  re- 
volved by  the  dental  engine  burnished  in  every  part  of  the  mold 
(Fig.  180).  To  facilitate  the  process,  the  mold  should  be  fre- 
quently opened,  and  the  gold  annealed.^  Fig.  181  represents  th& 
completed  crown.  These  results  can  be  secured  by  other  styles  of 
molds.     Fig.  180  illustrates  one,  but  the  principle  is  the  same. 


Fig.  180. 


Fig.  181. 


Another  method  is  to  form  a  fusible-metal  die  of  the  tooth  to- 
be  crowned,  and,  after  having  stamped  the  grinding-surface  of 
the  crown,  to  reverse  and  swage  the  sides  close  to  the  die;  the 
crown  is  then  relieved  of  the  core  (die)  by  heating  to  the  melting 
point  of  the  fusible  metal  and  pouring  it  out. 

For  practical  use,  a  variety  of  molds  is  required,  made  from, 
natural  teeth  of  different  sizes  and  average  forms  to  serve  in 
corresponding  cases.  The  crowns  can  be  contracted  at  the  neck 
more  than  their  size  and  contour  call  for,  so  that  the  gold  will 
act  as  a  tight-fitting  band  which  will  expand  to  the  form  of  the 
root  as  the  crown  is  pressed  up  in  the  process  of  adjustment. 

Caps  of  metal  can  be  made  in  different  sizes  and  kept  on  hand 
for  use  in  this  and  other  styles  of  crown- work  by  means  of  a 
machine  (Fig.  182),  which  in  principle  is  such  as  is  used  by 
jewelers  for  forming  cap-shaped  pieces  of  gold,  and  in  factories 
for  making  copper  cartridges.     The  gold  plate,  cut  into  circiilar 


G()l/D  SKAMIJISS  COSTOVi:  ('/,'<)  W.\S. 


101 


pieces,  is  pressed  tliroiigh  a  steel  die-plate,  with  punches  gauged 
to  the  holes;  at  each  pinich  a  small  ])ortion  of  the  gold  is  turned 


Fid.  182. 


The  form  of  stamping  machine  introduced  bj-  the  late  Dr.  J.  J.  R.  Patrick. 

over,  thus  preventing  its  lapping  or  creasing  (Fig.   183).     Re- 
peated annealing  of  the  metal  is  very  necessary  in  this  process. 
Fig.  183.  Fig.  184. 


O  O  @@ 


\ 


Methods  of  Contouring  Crowns  constructed  in 
Sections. — In  constructing  a  crown  in  sections,  the 
collar  can  be  first  formed  on  a  mandrel,  then  placed 
in  a  mold,  and  burnished  to  the  shape  of  the  sides. 
The  process  of  its  adjustment  to  the  neck  of  the  root  is  then  con- 
tinued in  the  usual  manner. 


102  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

Another  method  is  to  stamp  or  burnish  np  the  collar  on  a  die 
representing  the  upper  sections  of  a  tooth,  designated  as  the  mid- 
dle and  cervical  third  (Fig.  184).  After  contouring  the  collar, 
the  cap  is  adjusted  and  soldered  on.  With  a  metallic  stamping 
plate  (see  page  87)  these  caps  are  quickly  made. 

ADJUSTMENT   OF   SEAMLESS   CONTOUR   CROWNS. 

A  superior  molar- — one  of  the  most  diilicult  teeth  to  operate 
on — will  serve  as  a  typical  case  to  illustrate  this  process.  The 
crown  or  root  is  first  shaped  and  if  necessary  built  down  with 
amalgam,  straight,  or  tapering  slightly  on  its  sides  toward  the 
occluding  surface,  as  described  at  page  37. 

Hoiu  to  Select  a  Suitable  Croivn. — The  width  of  the  crown  re- 
quired from  the  anterior  to  the  posterior  sides  of  the  occluding 
surface  is  first  obtained  by  measurement  with  a  piece  of  card- 
board or  thin  copper  plate,  as  shown  at 
A,  Figs.  185  and  189.  The  measurement 
can  be  taken  direct  from  the  mouth,  or 
more  conveniently  from  a  small  plaster 
cast  made  from  a  correct  impression  of  the 
prepared  crown  or  root  and  the  two  ap- 
proximal  teeth.  With  this  measurement 
as  a  guide,  the  proper-sized  occluding  surface  is  readily  found 
by  comparison  with  the  dimensions  of  the  various  crowns  as  shown 
on  the  printed  chart  of  the  crowns  (C,  Figs.  186  and  187). 

The  size  of  the  neck  can  be  gauged  by  the  eye,  or  by  taking  the 
dimensions  with  a  piece  of  fine  wire  (Fig.  190),  pressing  the 
wire  on  the  surface  of  a  piece  of  sheet  wax,  and  then  comparing 
with  the  impression  the  necks  of  the  gold  crowns. 

In  making  a  selection,  it  should  be  borne  in  mind  that  the 
cervix  of  the  gold  crown  should  preferably  be  smaller  than  larger, 
as  it  can  always  be  easily  expanded,  while  its  contraction  is  diffi- 
cult. It  is  not  essential  that  the  curve  of  the  collar  shall  corre- 
spond with  that  of  the  tooth,  as  the  gold  will  readily  take  the 
proper  shape  as  the  crown  is  adjusted. 

MetJiod  of  Adjusting  the  Crown. — 1.  Anneal  the  crown  se- 
lected, and  slip  it  over  the  end  of  the  natural  crown  or  root  and 
gently  press  or  work  it  upward — the  gold  of  the  collar  will  expand 


(^()L1>  SEAMLESS  roA'/'O/'A'  (JliOWWS. 


103 


to  the  form  of  the  root  in  the  operation — until  the  edge  meets  the 
margin  of  the  gum  (A,  Tig.  188). 

2.  Mark  a  line  (B)  on  the  gold  parallel  with  the  margin  of 


the  gum. 


Fi(i.  186. 


Fk;.  187. 
A 


0- 

\ 
) 


cm^ 


Via.  If 


3.  Remove  and  trim  to  this  line  (A,  Fig.  191).  If  necessary, 
repeat  the  marking  and  trimming  until  the  edge  meets  the  gum 
evenly. 

4.  Bevel  the  edge  of  the  gold,  readjust  the  crown  and  press 
it  up  until  the  edge  of  the  collar  passes  under  the  margin  of  the 
gum,  and,  if  the  occlusion  is  correct,  burnish  the  gold  to  the 
cervix. 


Pig.  190. 


Fig.  191. 


To  Expand  the  Collar  and  Croiun. — If  the  collar  of  the  crown 
needs  enlargement,  it  is  easily  and  most  properly  accomplished 
with  crown  expanders  (shown  in  miniature  form  in  Fig.  192), 
the  points  of  which  should  be  introduced  at  first  just  within  the 


104 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


edge  of  the  neck,  and  the  gold  spread  sufficiently  to  allow  it  to 
fit  over  the  end  of  the  natural  crown  or  root,  the  process  of  ex- 
pansion being  gradually  continued  as  the  crown  is  brought  into 
position.  By  proceeding  in  this  manner  too  great  expansion  is 
avoided. 

To  Alter  a  Side. — The  contour  of  one  or  hoth  sides  can  he  de- 
pressed and  the  crown  thus  narrowed  by  introducing  the  points  of 
a  crown  expander  or  some  tool  that  will  fit  loosely  inside  the  crown, 


Pig.  192. 


Fig.  193. 


then  steadying  the  crown  with  the  fingers,  as  shown  in  Fig.  194, 
and  tapping  the  sides  to  be  reduced  with  the  flat  end  of  a  riveting 
hammer.  Pliers  will  also  accomplish  it,  one  beak  being  placed 
inside  of  the  crown,  and  the  other  being  placed  against  the  bulge 
on  the  outside  (Fig.  193).  This  is  necessary  when  the  contour 
or  the  side  of  a  crown  presses  on  an  adjoining  tooth,  and  the 
crown  is  thus  prevented  from  coming  in  proper  position. 

To  Alter  the  'Shape  of  a  Portion  of  the  Collar  or  Side  of  a 
Croivn. — Slip  the  crown  over  the  point  of  an  anvil,  or  the  end 
of  a  pair  of  expanders,  or  a  small  round-handled  instrument  held 
in  a  vise,  and  then  tap  the  part  to  be  altered  with  the  flat  end  of 
a  riveting  hammer  to  the  form  desired. 

To  Alter  the  Occluding  Surface. — Before  the  crown  is  pressed 
up  to  its  apparently  proper  position,   the   occlusion  should  be 


UOIJ)  SEAMLESS  COXTOtlh'  ('HOWSS. 


105 


examined,  and  calculations  carefully  made  to  ol)viate  any  defects 
of  articulation,  which  can  be  readily  corrected  at  this  stage  by 
proper  manipulation  of  the  crown. 


Fk;.    194. 


Fn;.   195. 


To  Alter  the  Grin  ding- Surface. — Place  crown  in  position  on 
the  tooth  and  flatten  the  part  with  a  large  gold  foil  condenser 
tapped  with  the  mallet,  or  hold  the  crown  and  tap  the  part  as 
shown  in  Fig.  195.  The  closing  of  the  antagonizing  teeth  upon 
the  crown  by  the  patient  with  force  will  aid  or  complete  the 
operation  of  articulating. 

To  Contract  the  Neck. — Slightly  bend  in  the  edge  of  the  gold 

at  the  neck  with  narrow-beaked  pliers,  and  holding  the  crown 

evenly  and  firmly  between  the  fingers,  as  shown  in  Fig.   196, 

burnish  the  sides  and  neck  section  inward 

Fig.  196.  around    the    entire    circumference    of    the 

crown. 

To  Consiclerahly  Contract  a  Croivn. — 
Slit  the  gold  longitudinally  at  the  palatal 
or  lingual  side  its  full  length  to  the  grind- 
ing-surface  as  shown  in  Fig.  197,  bevel  off 
the  edge  to  lap  under,  con-         fic4.  i97. 
tract   the   crown,   readjust 
to      the      tooth,      remove, 
place  the  smallest  quantity 
of    dampened    flux    solder 
filings  in  the  seam  on  the  inside  of  the  crown  only,  and  solder  by 
holding  in  an  alcohol  flame.      Then  proceed  with  the  further  ad- 
justment of  the  crown. 


106 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  outside  line  of  the  seam  can  be  stoned  off  and  polished  after 
the  crown  has  been  fitted,  and  additionally  soldered  to  strengthen 
the  sides  or  grinding-surface. 

To  Alter  the  Shape  of  a  Portion  of  the  Collar  or  Side  of  a 
Crown. — Slip  the  crown  over  the  point  of  an  anvil,  or  the  end  of 
a  pair  of  expanders,  or  a  small  round-handled  instrument  held 
in  a  vise,  and  then  tap  the  part  to  be  altered  with  the  flat  end 
of  a  riveting  hammer  to  the  form  desired. 

To  Deepen  the  Cusps. — Trim  a  piece  of  wood  to  the  form 
shown  in  Fig.  198,  rest  the  neck  on  a  flat  surface  and  press  the 
Avood  between  the  cusps. 


Fig.  198. 


Fig.  199. 


Fig.  200. 


2^0  point,  lengthen,  or  narrow  in  appearance  the  labial  cusp 
of  an  upper  bicuspid  crown,  gently  tap  the  gold  on  each  side  of 
the  labial  cusp  toward  the  point  at  the  angle  shown  in  Fig.  199. 

To  remove  the  indentation  between  the  cusps  and  thus  flatten 
the  whole  grinding-surface,  introduce  inside  the  crown  a  flat- 
'ended  piece  of  wood  the  size  of  the  crown  and  press  downward  as 
shown  in  Fig.  200. 

Strengthening  Seamless  Gold  Contour  Crowns. — Additional 
strength  and  stiffness  can  be  given  to  seamless  gold  crowns,  when 
desired,  in  several  ways.,  The  liability  of  melting  the  gold  which 
forms  the  side  of  the  crown  in  the  operation  has,  with  some,  been 
the  principal  objection  to  their  use.  This,  however,  can  be 
avoided. 

When  the  crown  has  been  properly  adjusted,  dampen  the  inner 
surface  with  a  piece  of  wet  cotton  on  the  point  of  an  instrument; 
place  in  the  interior  a  quantity  of  fluxed  solder  filings  (solder 
filings  mixed  with  Parr's  flux  or  pulverized  vitrified  borax) ;  place 


ooIjD  sk  am  less  coyroLR  crowns.  107 

the  finger  over  the  open  end  of  the  crown,  invert,  and  shake  well. 
A  portion  of  the  solder  filings  will  adhere  evenly  all  over  the  wet 
surface.  The  surplus  is  allowed  to  drop  out  by  removing  the 
finger.  Then  gradually  and  uniformly  heat  the  crown  by  holding 
it  with  tweezers  in  an  alcoJiol  flame  until  the  solder  fuses,  Avhen  it 
will  flow  evenly  over  the  surface  of  the  gold  without  materially 
altering  the  general  form.  The  crown  should  be  held  in  such  a 
position  that  a  full  view  of  the  interior  is  presented  and  the  melt- 
ing of  the  solder  rendered  visible,  which  will  occur  at  a  red  heat. 

An  extra  quantity  of  the  solder  filings  can  be  placed  in  tne 
interior  of  the  cusps  with  a  spoon-shaped  excavator  to  additionally 
fill  or  strengthen  them  if  found  necessary. 

When  a  Bunsen  gas  flame  is  used  instead  of  an  alcohol  flame, 
the  gold  must  not  be  brought  above  a  dull  red  heat.  The  grind- 
ing-surface  and  sides  of  the  crown  might  be  first  coated  with  whit- 
ing as  a  safeguard.  This  is  easily  done  by  dipping  the  crown  into 
a  cream-like  mixture  of  whiting  just  before  inserting  it  in  the 
flame.  The  moisture  in  the  whiting  should  be  first  slowly  evapor- 
ated by  heating  up  gradually.  Great  care  must  be  exercised 
in  the  use  of  a  gas  flame  to  avoid  melting  the  crown.  The  cro^'vai 
should  be  watched,  and  instantly  removed  as  soon  as  the  solder 
fuses  and  flows.-*- 

If  too  much  solder  has  been  applied  at  any  point,  it  can  be 
trimmed  and  smoothed  with  corundum  melted  on  to  an  old  engine 
bur-point.  Always  boil  the  crown  in  acid  to  remove  the  flux. 
The  removal  of  flux  from  the  inner  surface  of  the  crown  is  abso- 
lutely necessary  if  you  intend  to  use  it  in  bridge-work,  as  solder 
will  have  to  be  melted  on  the  outside. 

To  repair  a  hole  melted  in  any  kind  of  a  gold  crown,  place  a 
piece  of  soft  wax  in  the  aperture,  on  the  outside  of  the  crown, 
adapt  on  the  inside  close  against  the  gold  a  piece  of  platinum 
foil,  somewhat  larger  than  the  aperture,  so  that  it  will  adhere  to 
the  wax.  Fill  the  interior  of  the  crown  with  investing  material, 
and  flow  a  little  solder  over  the  surface  of  the  platinum,  and  gold 
on  the  outside  of  the  crown. 

Gold  seamless  crowns  can  also  be  strengthened  or  filled  wich 

1 18-carat  gold  plate  can  be  molted  in  the  "Evans  Crowns"  as  safely  as   solder 
if  heated  up  slowly. 


108 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  201. 


solder,  or  even  18-  or  20-carat  gold  plate,  by  investing  the  outside 
surface  in  plaster  and  marble-diist  (Fig.  201),  and  then  with  a 
small  flame  of  the  carbo-oxyhydrogen  blow-pipe,  not  over  one- 
half  inch  in  length,  introduced  inside  of  the  crown,  melt  and 
flow  the  solder  or  gold  plate  over  any  portion  or  even  all  of  the 
surface  of  the  gold.  The  crown,  if  formed  of  gold  even  with 
a  thin  lining  of  platinum,  can  be  soldered  by 
either  method  with  little  danger  of  being  melted. 
Another  method  to  thicken  the  grinding-sur- 
face  is:  Scratch  the  inside  surface  of  the  gold 
cusp  and  pack  evenly  against  it  freshly  annealed 
pellets  of  gold  with  a  sharp  plugger.  The  gold 
will  adhere,  and  when  burnished  with  a  revolv- 
ing agate  point  will  form  solid  gold  cusps.  If 
desired,  the  gold  foil  can  be  even  fused  in  the 
cusps,  after  being  packed,  by  heating  up  slowly 
in  a  Bunsen  flame,  or  a  partich?  of  solder  filings  can  be  melted 
•over  it. 

Supporting  the  Croivn. — In  crowning  teeth  with  living  pulps 
there  is  sufficient  of  the  natural  crown  present  to  afford  a  secure 
foundation  and  attachment  for  the  artificial  crown,  as  is  also  the 
case  with  many  teeth  that  are  pulpless;  but  in  badly  broken- 
down  crowns,  or  where  only  the  root  is  present,  a  metallic  pin 
or  post  should  be  inserted  in  the  root,  and  the  part 
built  down  with  amalgam  to  a  form  which  will  afford 
secure  support  and  attachment  to  the  artificial  crown, 
and  facilitate  its  adjustment.  (See  "Special  Prepa- 
ration of  Badly  Decayed  Teeth  or  Roots,"  page  38.) 
In  many  cases  the  required  support  for  the  crown 
•can  be  secured  by  means  of  a  screw  (Fig.  202).  A 
How  screw  or  post  of  silver  wire  is  inserted  in  the 
root-canal  A  (see  page  47).  Amalgam  is  then  packed 
in  the  lower  section  of  the  artificial  crown,  C,  to  the 
line  B,  and  into  the  amalgam  the  screw  is  pressed.  Amalgam 
which  has  been  put  in  a  piece  of  chamois  and  the  mercury  pressed 
out  with  a  pair  of  pliers  until  it  is  in  the  condition  termed  "dry" 
will  adhere  to  the  gold  without  affecting  it.  The  amalgam  is 
first  placed  in  the  crown  slightly  in  excess  of  the  amount  required, 
and  the  crown  adjusted,  removed,  and  the  surplus  scraped  out. 


Fig.  202. 


OOLD  SKAMLKSS  (JO^T'HJIi  C'UOUWS. 


1Q9 


This  process  is  continued  until  the  screw  or  the  crown  section  of 
the  natural  tooth  forms  an  indentation  in  the  amalgam,  which  it 
will  fit  when  the  crown  is  cemented  on.  (For  process  of  cemen- 
tation, see  article  on  ''Insertion  and  Cementation.") 

These  crowns  can  be  inserted  in  an  easy  and  inexpensive  man- 
ner by  filling-  in  the  lower  section  of  the  crown  with  amalgam 
instead  of  gold,  and  allowing  the  head  of  the  screw  or  the  natural 
crown  to  indent  the  amalgam  as  above  described,  and  then  ce- 
menting on  the  crown  with  oxyphosphate  in  the  usual  manner. 

In  a  case  so  inserted,  with  no  antagonizing  teeth,  the  result  is 
the  same  as  though  the  inside  of  the  occluding  surface  of  the 
crown  was  filled  with  gold;  but  if  antagonizing  teeth  are  present, 
the  gold  of  the  crown  is  apt  to  wear  through  in  places  and  expose 
the  amalgam. 


Fig.  203. 


Fig.  204. 


Fig.  205. 


To  Securely  Attach  a  Croivn. — If  the  tooth  is  short,  and  the 
occlusion  of  a  character  requiring  the  reduction  of  the  collar  to 
such  a  degree  as  to  suggest  insecurity  when  the  crown  is  ce- 
mented, a  barbed  or  headed  pin,  which  will  anchor  in  the  natural 
crown  or  root,  should  be  soldered  in  the  center  of  the  gold  crown, 
as  shown  in  Fig.  203.  This  is  done  by  passing  the  pin  through 
a  hole  drilled  in  the  occluding  surface  of  the  crown,  Avhich  is  then 
adjusted  in  the  mouth,  removed,  invested,  and  the  pin  soldered 
from  the  outside.  If  the  pin  is  tapered  and  fitted  tightly  to  the 
hole  (Fig.  204),  the  soldering  can  be  accomplished  without  in- 
vesting, by  holding  the  crown  and  pin  with  solder  in  position  in 
an  alcohol  flame. 

To  Alter  a  Gold  Crown  to  the  Exact  Form  of  any  Correspond- 
ing Natural  One. — In  a  case  having  nearly  all  the  natural  teeth 
present,  in  which  the  occluding  surface  and  sides  differ  in  shape 
from  the  form  of  the  gold  crown,  to  such  an  extent  as  to  inter- 
fere with  its  adjustment,  a  die  of  the  natural  crown  should  be 


110  ARTIFJCIAL  CROWN-  AND  BRIDGE-WORK. 

made  of  fusible  metal  (Melotte's  Fusible  Alloy ,^ — see  article  on 
"Molds  and  Dies"),  and  with  it  the  interior  of  the  gold  crown 
should  be  altered  in  shape  sufficiently  to  receive  the  natural  crown, 
by  resting  the  occluding  surface  of  the  gold  crown  on  a  folded 
napkin  and  gently  tapping  the  die  into  it.  By  this  means  a  ready- 
made  gold  crown  is  quickly  altered  to  the  exact  shape  of  any  tooth 
and  is  qualified  to  meet  all  requirements. 

Fig.  205  represents  the  typical  molar  crown  cemented  in  posi- 
tion. 

The  advantages  of  seamless  contour  crowns  are,  that  they  rep- 
resent perfectly  the  tooth  in  its  anatomical  contour,  present  a 
uniform  surface  of  pure  gold,  which  preserves  its  color  without 
tarnishing,  and  are  quickly  and  easily  adjusted. 


CHAPTER    IX. 

.SPECIAL  FORMS  OF  GOLD  OJIOWNS  WITH   I'OK("ELAIN  FRONTS. 

PORCELAIN    AND   GOLD    CROWN    WITHOUT   A   COLLAR,   AND 
PARTIAL  COLLAR   CROWNS. 

The  root  of  a  cuspid  will  be  taken  as  a  typical  case  to  illustrate 
the  construction  of  this  style  of  crown. 

The  end  of  the  root  is  prepared  the  same  as  for  a  porcelain 
crown  (Fig,  206).  The  root-canal  is  then  uniformly  enlarged  a 
reasonable  distance  up,  with  a  drill  which  will  closely  fit  the  open- 
ing.    Into  the  canal,  gauging  its  full  diameter,  is  fitted  a  piece 


Fi(i.  206. 


Fig.  207. 


CD 


Fui.  208. 


Fif,.  209. 


Fig.  210. 


of  iridio-platinum  Avire,  tapered  off  to  a  point,  so  that  by  intro- 
ducing it  far  up  the  canal  greater  strength  can  be  obtained,  and 
the  root  rendered  less  liable  to  longitudinal  fracture  from  pressure 
in  a  forward  direction.  A  piece  of  platinum  plate,  a  trifle  larger 
than  the  end  of  the  root,  of  about  'No.  30  U.  S.  standard  gauge, 
with  a  hole  punched  in  its  center,  is  then  slipped  on  the  post, 
which  it  must  fit  tightly  (Fig.  207). 

"When  the  post  is  adjusted  firmly  in  the  canal,  the  platinum 
plate  is  pressed  down  on  the  root,  and  burnished  into  the  orifice 
of  the  canal  around  the  post.     When  the  post  is  Avithdrawn  from 
the  root,  the  platinum  will  adhere  to  it,  if  fitted  closely,  with- 
in 


112  ARTIFICIAL  GROWN- AND  BRIDGE-WORK. 

out  the  use  of  wax.  A  particle  of  pure  gold  with  borax  is  put 
in  the  joint,  and  melted  in  the  flame  of  an  alcohol  lamp.  Barely 
enough  gold  should  be  used  to  unite  the  parts.  When  soldered, 
the  post  and  cap  are  again  adjusted  in  the  mouth  and  the  cap 
malleted  and  burnished  to  the  form  of  the  end  of  the  root,  so 
that  its  edge  will  leave  a  mark  on  the  platinum.  The  cap,  on 
being  removed,  should  be  trimmed  to  this  mark,  and  again  bur- 
nished on  the  root  (Fig.  208).  Sometimes  around  the  palatal 
portion  of  the  root  the  platinum  may  be  slightly  burnished  over 
the  edge.  The  post  is  then  cut  off  just  above  the  platinum,  and  a 
plate  tooth  fitted,  backed,  and  cemented  with  wax  in  position  on 
the  cap,  as  described  on  page  85...  The  whole  is  then  removed, 
invested,  and  soldered  with  gold,  Avhich  should  be  melted  in  at 
the  base  of  the  post,  as  at  this  point,  when  in  use,  the  strain  is 
very  great.  The  post  is  then  barbed,  and  the  crown  is  cemented 
to  the  root  Avith  gutta-percha  or  oxyphosphate  cement  (Fig.  209). 
Dr.  F.  T.  Van  AVoert,  of  Brooklyn,  IN".  Y.,  in  constructing 
Fig.  211.  crowiis  without  collars,  shapes  the  end  of  the 

root,  and  adapts  the  cap  as  shown  in  Fig.  210. 
A       The  slant  given  to  the  palatal  side  aids  the  root 
■^S    to  resist  force  in  a  forward  direction. 

Partial  Collar  C rowns.—T\\e  advantages  of  a 
collar  can  in  a  great  measure  be  given  this  form 
of  crown  by  the  addition  of  a  metal  flange,  encir- 
cling the  palatal  section  of  the  root,  as  shown  in  Fig.  211.  A 
piece  of  gold  or  platinum,  similar  in  shape  to  that  shown  at  A, 
is  formed  and  fitted  to  the  crown,  fixed  in  position  on  the  crown 
with  wax,  and  adjusted  in  the  mouth,  removed,  invested,  and  sol- 
dered. After  finishing,  the  metal  flange  is  burnished  against  the 
root  before  the  crown  is  cemented. 

Dr.  T.  F.  Chupein's  method  to  form  a  partial  collar  cap  for  a 
root  is:  Cut  a  strip  of  platinum  of  about  jSTo.  32,  or  gold  plate  of 
ISTo.  30  gauge  to  the  shape  shown  in  Fig.  212;  for  instance,  for  an 
incisor.  Bend  the  metal  to  the  form  illustrated  in  Fig.  213. 
Place  the  collar  on  the  root  with  the  broad  portion  at  the  labial 
side.  Grasp  the  ends  with  pliers  and  draw  the  metal  tightly  to- 
gether against  the  sides.  Remove  and  solder  the  ends  together 
(Fig.  214).  Trim  the  edge  of  the  collar  to  the  surface  of  the  root. 
Solder  on  a  thin  piece  of  platinum  plate  to  form  the  cap  (Fig.  215), 


aor/D  <;it()\v.\s  with  I'ohci'j.ms  fho.xts. 


113 


and  remove  the  surplus  plate  and  projecting  ends  and  the  labial 
section  of  the  collar  (Fig.  216).  The  cap  is  then  ready  to  have  the 
post  fitted  and  soldered  to  it  in  position  (Fig.  217). 


Fig.  212. 


Fig.  213. 


Fig.  214. 


Fig.  215. 


Fig.  216. 


Fig.  217. 


Post  and  Dish  Method. — Ready-made  posts  corresponding  in 
size  to  the  Ottolengui  reamers,  Fig.  72,  with  disks  of  platinum, 
can  be  used  to  facilitate  the  construction  of  crowns  of  this  style. 

The  posts  are  illustrated  in  Fig.  220.  A  disk  of  platinum 
with  a  perforated  depression  in  which  a  little  gold  has  been  melted 
is  shov»ni  in  Figs.  221  and  222. 

The  method  is  as  follows: 

Shape  the  surface  of  the  end  of  the  root  as  shown  laterally  in 
Fig.  218. 

Trim  the  approximal  and  palatal  sides  of  the  end  of  the  root, 
as  illustrated  in  Fig.  219,  but  leave  the  labial  side  A,  intact. 

Fig.  218. 


Enlarge  and  ream  the  root-canal  with  Ottolengui  root-canal 
reamers,  shown  in  Fig.  72,  to  the  proper  depth,  first  using  the 
smallest  size,  and  if  necessary  the  larger  sizes  afterward. 

-Select  a  post  (Fig.  220)  corresponding  in  number  to  that  of  the 
reamer  used.  Seize  the  large  end  of  the  post  with  the  points  of 
the  pliers  and  fit  the  post  to  the  canal.     Move  the  post  up  and 

9 


114  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

down — but  do  not  twist — a  few  times  in  the  canal,  and  the  slight- 
est discrepancy  that  may  exist  respecting  size  will  be  instantly  re- 
moved. 

Grasp  the  post  when  fitted  in  the  canal  with  the  pliers,  having 
the  points  close  to  the  surface  of  the  end  of  the  root.  Remove 
the  post  without  moving  the  position  of  the  pliers.  Screw  the 
post  into  the  hole  in  the  depression  of  the  platinum  disk,  shown 
in  Fig,  221  and  in  section  in  Fig.  222,  up  to  the  points  of  the 
pliers,  thus  giving  the  post  its  position  in  the  disk. 

Bend  the  sides  of  the  disk  downward,  as  shown  in  Fig.  223, 
and  adjust  the  post  in  the  canal  to  determine  their  relative  posi- 
tions. By  twisting  the  post,  changes  of  its  position  in  the  disk 
may  be  effected. 

Fig.  220.  Fig.  221.  Fig.  222.  Fig.  223. 


o 


The  orifice  of  the  canal  of  the  root  should  be  slightly  enlarged 
with  a  round  bur  to  allow  the  depression  of  the  disk  to  fit  within 
it.  Press  the  post  firmly  upward  in  the  root-canal  to  assure  that, 
its  original  position  is  not  interfered  with  by  the  disk. 

Remove  the  post  and  disk,  the  disk  retaining  its  position  on  the 
post.  Unite  post  and  disk  by  holding  them  in  a  Bunsen  gas- 
flame  until  the  pure  gold  in  the  depression  is  fused.  No  flux 
is  necessary,  as  sufficient  remains  from  the  fusion  of  the  gold  in 
the  depression. 

Fig.  224  Place  the  post  and  disk  on  the  root,  and  press  and  mal- 
let the  platinum  to  it  with  a  large  flat  plugger,  which,, 
owing  to  the  rigidity  of  the  post  in  the  canal,  will  ac- 
curately outline  the  form  of  the  end  of  the  root  on  the 
platinum.  Remove  and  slit  the  platinum  at  two  points 
between  the  palatal  and  approximal  sides  to  the  outline 
of  the  end  of  the  root  as  shown  in  Fig.  224,  at  A  and  B,  and 
bend  the  platinum  over  with  the  pliers  to  embrace  the  approximal 
sides  of  the  root. 


MOUSTISd   THE   I'OnCELMS   FROyT.  115 

Again  j^lace  the  post  and  cap  on  the  root,  and  closely  fit  the 
side  flaps,  with  the  aid  of  foot-shaped  condensers  and  burnishers. 
jSText  bring  the  palatal  flap  down  to  position.  Frequent  removals 
and  annealings  are  necessary  during  the  process,  which  should 
include  the  final  trimming  of  the  edge  of  the  platinum,  smooth- 
ing with  a  corundum-point,  and  then  an  annealing  and  all-round 
burnishing  of  the  cap  to  the  root.  Cut  off  the  end  of  the  post 
above  the  cap  with  a  corundum-disk  and  level  mth  a  wheel.  The 
cap  can  now  be  invested  and  the  seams  soldered,  or  this  can  be 
done  in  the  soldering  on  of  the  porcelain  front. 

MOUNTING   THE    PORCELAIN    FRONT. 

At  the  cervico-labial  section  the  porcelain  can  rest  on  the 
platinum,  or  the  platinum  can  be  trimmed,  so  that  the  front  edge 
of  the  porcelain  may  be  fitted  against  the  root,  and  cover  it.  (See 
Fig.  225.)  The  projecting  end  of  the  post  should  also  be  re- 
moved l^y  first  notching  with  a  disk,  leaving  it  a  little  flush  at  the 

Tig.  225.  Fig.  220.  Fig.  227. 


palatal  side.  The  porcelain  front,  which  should  be  a  cross-pin 
plate  tooth,  is  ground  and  closely  fitted  to  the  surface  of  the  root 
or  metal,  as  may  be,  at  the  cervico-labial  section  under  the  edge 
of  the  gum,  but  a  properly  shaped  space  opening  toward  the  palatal 
side  is  left  between  it  and  the  surface  of  the  cap.  To  so  shape 
the  porcelain  simplifies  the  fitting  of  the  cervical  section.  The 
space  between  the  cap  and  the  porcelain  is  also  easier  filled  in 
the  soldering.  To  the  porcelain  front  at  the  part  B,  Fig.  226,  a 
piece  of  very  thin  platinum  foil  is  shaped,  the  porcelain  heated^ 
the  part  veneered  with  a  mere  film  of  resin  and  wax,  and  by 
pressure  with  napkin  or  cotton  the  platinum  foil  is  attached 
thereto.  The  rest  of  the  porcelain  is  then  backed  with  thin  plati- 
num plate  (about  ISTo.  34  gauge).     The  platinum  is  left  slightly 


116  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

extending  over  the  incisive  edge,  and  the  porcelain  front  is  waxed 
in  position  on  the  cap. 

Fig.  225  shows  the  crown  waxed  up  ready  for  investment.- 
3Vax  in  fnll  quantity  must  be  extended  over  the  collar  to  its  edge, 
in  the  seams,  and  between  the  porcelain  and  the  cap  at  every 
point  solder  is  to  flow  (the  writer  uses  Parr's  fluxed  wax).  Fig. 
227  shows  the  invested  crown  with  the  wax  removed.  In  trim- 
ming the  investment  the  material  must  not  be  removed  from 
over  the  collar  lower  than  the  line  of  the  surface  of  the  cap,  nor 
in  such  a  manner  that  the  platinum  turn-over  edges  are  exposed 
to  the  direct  force  of  the  flame.  Even  though  the  collar  is  not 
exposed,  the  s.older  will  flow  over  the  outer  surface  of  the  plati- 
num just  where  it  is  wanted  and  where  wax  has  been  applied, 
and  all  the  parts  will  become  united.  The  investment  must  be 
slightly  raised  at  one  end  and  heated  up  under  its  base  with  the 
full  flame  of  a  gas  blow-pipe  thrown  in  the  direction  indicated 
by  the  arrow  in  Fig.  227.  Heat  thus  applied  will  cause  the 
solder  to  flow  downward  by  gravitation  and  fill  the  interstices 
in  all  parts  of  the  investment  as  though  it  were  an  ingot.  The 
best  way  is  to  apply  solder  a  little  at  a  time  until  the  deep  parts 
are  filled.  The  flame  is  withdrawn  for  an  instant,  and  with  a  small 
pointed  flame  and  more  solder  the  backing  contoured.  As  plati- 
num forms  the  cap  and  backing,  the  soldering  can  be  conducted 
without  fear  of  accidentally  fusing  those  parts.  Unless  the  sol- 
dering is  conducted  as  described,  the  two  seams  of  the  cap  should 
be  previously  soldered. 

THE   PARR   CROWN. 

The  advantage  of  this  form  of  crown  is  that  the  root  is  securely 
and  permanently  capped  independently  of  the  crown,  which  can 
be  removed  without  disturbing  the  cap  on  the  root.  For  use  in 
crown-  and  bridge-work  the  outer  cap  may  be  made  with  a  band 
which  half  encircles  the  inner-  cap,  and  tapers  off  from  the  palatal 
to  the  labial  section,  as  illustrated  in  Fig.  230.  The  cap  on  the 
root  is  cemented  with  oxyphosphate,  and  the  post  and  outer  cap 
with  gutta-percha. 

The  root  is  prepared,  banded,  and  capped  without  a  pin,  the 
same  as  for  a  gold  collar  crown  (A,  Fig.  228).  A  hole  is  made 
in  the  cap,  and  a  post  fitted  in  the  canal.     A  piece  of  gold  plate. 


77//-;  LKEcn  cnows. 


117 


fully  the  size  of  the  cap  on  the  root,  is  adjusted  on  the  post  above 
the  cap  by  making  a  hole  in  the  gold  in  which  the  post  will  fit 
tightly.     The  gold  plate  is  then  adapted  to  the  cap  on  the  root, 


Pig.  228. 


Fk;.   229. 


Fig.  230. 


and  burnished,  without  a  collar,  around  the  post,  form-    \    ,vw 
ing  an  outside  cap ;  the  pin  and  the  outer  cap  are  then  re-      \w 
moved  and  soldered  together  and  adjusted  on  the  inner 
cap,  and  the  edge  of  the  outer  cap  trimmed  even  with  it  (B).     The 
porcelain  tooth  to  form  the  crown,  C,  is  fitted  and  attached  to  the 
outer  cap,  which,  when  finished,  is  cemented  in  position  as  shown 


in  Fig.  229. 


THE   LEECH    CROWN. 


Fig.  2.S1. 


Dr.  Leech's  crown  is  thns  described  by  Dr.  J.  E.  Dexter:' 
"A  method  devised  by  Dr.  H.  Iv.  Leech,  of  Philadelphia,  shown 
in  Fig.  231,  and  described  in  the  Dental  Cosmos  for  April,  1879, 
is  as  follows:  The  root  is  drilled  out  to  a  depth  of  about  three- 
eighths   of   an   inch   in    diameter   of 
about  'No.   16,  standard  (American) 
wire  gauge^  the  bottom  of  the  hole 
being    flared    or    enlarged,    and    the 
canal  above  filled  with  gutta-percha. 
A  gold  tube  is  made  to  fit  the  hole 
accurately  and  project  sufiiciently  for 
convenience  of  handling,  and  is  sol- 
dered through  a  hole  in  a  gold  base 
struck  to  the  root,  projecting  through 
the    plate    some    distance;     A    plate 
tooth  is  fitted  to  the  root  and  plate  and  soldered  to  the  latter. 


ri 


i>-4 


Denial  Cosi 


May,  1883. 


118  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

gold  being  flowed  onto  the  plate  and  backing  and  around  the 
projecting  tube  to  form  the  palatal  contour,  and  the  tube  cut  off 
flush  with  the  latter.  We  now  have  a  plate  tooth,  gold  backed, 
with  a  tube-pivot,  the  orifice  of  which  opens  on  the  palatal  aspect 
of  our  tooth.  The  root-end  of  the  tube  is  now  slit  perpendicularly 
in  three  or  four  places,  for  about  two-thirds  of  its  length,  a  thin 
sheet  of  warmed  gutta-percha  is  placed  on  the  base  of  the  crown 
around  the  tube,  and  the  whole  is  pushed  securely  to  place.  ISTow 
pack  gold  or  tin  into  the  tube,  condensing  the  hottom  portions  so 
that  the  slit  end  will  spread  and  tightly  fill  the  flared  end  of  the 
hole  in  the  root,  and  the  operation  is  complete." 

A  collar  'crown  fastened  with  a  tube-pivot  as  described  can  be 
used  to  advantage  in  detachable  bridge-work,  as  the  tube  if  filled 
with  tin  foil  will  admit  of  the  crown  being  easily  detached. 

THE    PERRY    CROWN. 

Dr.  Safford  G.  Perry,  of  jSTew  York,  employs  a  porcelain  crown 
in  combination  with  a  capped  root.     A  bicuspid  will  be  taken 
as  a  typical  case  to  illustrate  Dr.  Perry's 
'  _,,.,^  method.     The  end  of  the  root,  by  trim- 

/!%  /     \  ming  the  edge,  is  given  the  tapering  form 

\  shown  at  A,  Fig.  232.     The  collar  (B)  is 

1  made  very  narrow.     A  cap  made  of  plati- 

I..D       num  soldered  with  pure  gold  is  fitted  on  the 
[  \  collar,  and  a  post  or  posts  fitted  in  the  root 

J  and  through  the  cap.     Enough  of  the  post 

is  allowed  to  extend  beyond  the  cap  to  at- 
tach and  firmly  retain  the  porcelain  crown  (C). 

A  suitable  Ilowland-Perry  porcelain  (see  page  49)  crown  (C, 
Fig.  232)  is  ground  and  fitted  in  proper  position  on  the  cap. 
This  operation  is  facilitated  by  perforating  a  disk  of  marking- 
paper  with  the  posts  and  adjusting  it  on  the  cap.  Then,  as  the 
crown  is  placed  on  the  cap  and  pressed  against  it,  points  which 
prevent  perfect  adjustment  are  marked  on  the  porcelain.  By 
this  means  a  close  joint  is  easily  secured.  The  edge  of  the  porce- 
lain should  be  fitted  under  the  free  margin  of  the  gum,  especially 
at  the  cervico-palatal  part.  The  jDorcelain  crown  is  next  set  over 
the  projecting  pins,  and  cemented  to  the  cap  with  oxyphosphate. 


THE  PERRV  fJROWX.  1^9 

The  advantage  of  this  method  is,  that  the  root  being  slightly 
tapered,  the  collar  can  be  made  to  fit  absolutely,  while  the  excess 
of  oxyphosphate  is  gotten  rid  of  through  the  vent-holes,  instead 
of  being  squeezed  out  around  the  edge  of  the  collar.  The  edge 
of  the  collar  being  made  to  a  knife-edge,  can  be  properly  bur- 
nished before  the  crown  is  placed,  so  that  it  will  not  irritate  the 
gum  or  make  a  shelf.  The  crown  covers  the  cap,  and  can  usually 
be  ground  and  fitted  so  as  to  entirely  hide  any  exposed  portion  of 
the  collar,  the  junction  of  which  with  the  cap  should  be  trimmed 
and  then  rounded  with  a  burnisher,  to  give  a  form  which  will 
better  meet  the  interior  of  the  porcelain  cap  or  crown.  The  por- 
celain can  be  replaced  at  any  time  in  case  of  fracture  without 
disturbing  the  cap  on  the  root.  Easy  repair,  simplicity  of  con- 
struction, and  artistic  result,  are  the  special  features  of  this  crown. 


CHAPTER   X. 

CEOWNING  FEACTURED  TEETH  AND  EOOTS— CEOWNING- 
MOLAE  EOOTS  DECAYED  APAET  AT  BIFUECATION— CEOWN- 
ING   IN   CASES   OF    lEEEGULAEITY. 

The  crowning  of  fractured  teetli  and  roots  is  a  process  that 
requires  skill  and  delicate  treatment.  Its  practicability  depends 
on  the  nature  of  the  fracture,  the  previous  health  of  the  parts, 
and  the  length  of  time  that  has  elapsed  since  the  occurrence  of 
the  injury. 

LONGITUDINAL   FRACTURE   OF  THE   CROWN   AND    ROOT. 

By  this  is  meant  a  fracture  extending  lengthwise  through  the 
crown  or  what  remains  of  it,  and  along  the  root  or  roots.  Foreign 
substances  having  been  removed  from  within  and  around  the  parts, 
the  crevice  of  the  fracture  is  syringed  thoroughly  with  tepid 
water  and  then  with  peroxid  of  hydrogen.  The  frarctured  parts 
of  the  root  are  then  drawn  together  with  waxed  floss  silk. 
Fig.  233.    p^ggg(j  g^^  least  twice  around  the  tooth,  and  tied,  the  ends 

®  being  passed  through  twice  in  forming  the  knot.  The 
pulp-chamber  is  then  prepared,  and  dovetail  slots  are 
drilled  across  the  parts  (Fig.  233). 
If  it  is  suspected  that  in  the  preparation  any  particles  of  den- 
tin have  invaded  the  crevice  of  the  fracture,  the  ligature  must 
be  removed,  the  parts  again  syringed,  and  the  ligature  readjusted. 
Aromatic  sulfuric  acid  followed  by  the  peroxid  can  be  recom- 
mended for  the  final  injections.  The  upper  parts  of  the  root- 
canals  are  then  filled  with  gutta-percha,  or,  preferably,  with  oxy- 
chlorid  of  zinc,  and  the  main  body  of  the  cavity  and  the  slots 
with  a  hard,  quick-setting  amalgam.  A  collar  crown  should  al- 
ways be  used  in  these  cases.  If  the  form  to  be  used  has  a  post, 
a  short,  small  tube  of  gold  or  platinum  should  be  set  in  the  amal- 
gam in  proper  position  to  receive  it.  At  the  next  visit  of  the 
patient  the  ligature  is  removed  and  the  parts  carefully  prepared 
120 


viiowNiNd  Fii.\cri:RED  Tiiiyrii  and  routs. 


121 


for  crowning.  Tlie  circumference  of  the  root  is  first  measured 
with  a  wire,  a  tight-fitting  collar  constructed,  and  the  crown  then 
completed  in  the  usual  manner.  The  crown  may  be  favored  by 
leaving  a  slight  space  between  its  occluding  surface  and  the  an- 
tagonizing tooth. 

The  great  drawback  in  these  cases  is  that  the  patient  generally 
fails  to  present  himself  immediately  for  treatment,  and  foreign 
substances  work  into  the  fracture,  causing  inflammation,  which  is 
difficult  to  control.  Often  subsequent  to  treatment  a  septic  con- 
dition of  the  fracture  supervenes,  the  irritation  caused  thereby 
and  the  exudations  from  the  fracture  becoming  so  annoying  that 
extraction  is  the  only  alternative. 

Teeth  fractured  as  above  described  are  rarely  found  with  living 
pulps. 

FRACTURE  OF  THE  CROWN  WITH  SLANTING  FRACTURE  OF 

THE  ROOT. 

Fractures  of  this  kind  are  common,  especially  in  bicuspids, 
where  large  fillings  are  inserted  extending  from  the  anterior  to 
the  posterior  approximal  walls,  leaving  the  separated  buccal  and 
palatal  cusps  to  bear  the  brunt  of  mastication. 

In  such  cases  the  fracture  seldom  extends  beyond  the  edge  of 
the  alveolar  process.     The  fractured  part  having  been  carefully 


Fia.  234. 


Fig.  235. 


removed,  a  dovetail  slot  is  made  in  the  crown  or  root,  in  which 
gutta-percha  is  inserted  for  a  day  and  the  membrane  of  the  gum 
pressed  back,  so  as  to  fully  expose  the  'surface  and  margins  of  the 
fracture.  The  form  of  the  neck  is  then  in  a  measure  restored  with 
amalgam,  which,  when  hard,  is  polished  (Figs.  234  and  235). 

The  tooth  or  root  is  then  crowned,  the  mode  of  operation  being 
the  same  as  in  any  other  case. 


122  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

PERFORATION    OF  A  SIDE-WALL    OF  A   ROOT-CANAL    OR    OF 
THE   DENTIN    AT   THE   BIFURCATION   OF   THE   ROOTS. 

Extensive  perforation  bj  decay  in  these  locations  below  the  line 
of  the  edge  of  the  alveolar  process  seldom  admits  of  successful 
treatment.  When  the  decay  is  of  limited  extent,  and  a  very  slight 
perforation  has  been  produced  by  its  thorough  removal  or  by  the 
improper  or  careless  use  of  a  bur,  cicatricial  tissue  may  be  induced 
to  form  over  the  part  by  creating  and  maintaining  a  sterilized  con- 
dition, and  then  sealing  the  cavity. 

The  method  of  procedure  is  as  follows:  First  effect  steriliza- 
tion of  the  dentin  and  canals.  Bathe  the  perforated  part  with 
peroxid  of  hydrogen.  Dry  the  canal  thoroughly.  Bathe  the 
edges  of  the  perforation  with  chloroform.  Fit  closely  over  the 
perforation  a  small,  flat  piece  of  gutta-percha,  warmed  and  applied 
with  a  gentle  pressure,  sufficient  only  to  produce  adhesion  vdth- 
out  forcing  the  gutta-percha  through.  The  filling  of  the  canal 
can  then  be  carefully  completed.  Oxychlorid  of  zinc  is  the  most 
suitable  in  these  cases,  as  no  pressure  is  required,  and  a  dense  anti- 
septic filling  in  the  roots  and  over  the  cap  on  the  perforation  is 
the  result.  If  this  method  proves  unsuccessful  and  inflammation 
ensues,  the  position  of  the  perforation  should 
be  carefully  calculated,  and  an  artificial 
fistula  should  be  formed  on  a  direct  line  with 
it  through  the  gum  and  alveolar  process  (see 
Fig.  236).  Carbolic  acid  may  be  used  as  de- 
scribed at  page  32,  to  obtund  the  tissue.  The 
necessary  perforation  through  the  alveolar 
process  should  be  small  in  diameter,  and  be 
made  with  a  drill.  Injections  can  be  made  outward  through  the 
fistula,  and  the  perforation  sealed  with  gutta-percha  similarly  to 
the  closing  of  a  foramen  in  cases  of  alveolar  abscess,  after  having 
previously  filled  the  canal  or  canals  above  the  perforation. 


CROW M NO  MOLAR  JKjOTS 


123 


CROWNING  MOLAR  ROOTS  DECAYED  APART  AT  THE 
BfFURCATION. 

The  roots  of  a  molar  decayed  apart  at  the  bifurcation  can  often 
be  crowned  serviceably  by  making  a  cap  for  each  root  separately, 

Fro.  237. 


rt]^-^^ 


and  then  soldering  the   sides  of  the   cap   together   (Fig.    237). 
Where  one  root  is  missing,  the  other  can  be  crowned  singly. 

DR.    FARRAR'S   CANTILEVER   CROWN. 

Figs.  238  and  239  represent  Dr.  J.  IST.  Farrar's  cantilever 
■crowns.  He  describes  them  as  follows:  Fig.  238  illustrates  a 
sectional  view  of  three  teeth,  and  an  amputated  first  bicuspid 
root  preserved  by  a  screw,  showing  the  application  of  the  canti- 
lever crown  T  P,  set  upon  the  decayed  second  bicuspid  and  made 


Fig.  238. 


Fig.  239. 


to  project  over  to  bridge  the  space  formed  by  the  loss  of  the  first 
bicuspid,  and  resting  in  contact  with  the  cuspid  so  as  to  connect 
the  broken  line  of  masticating  surfaces  and  prevent  tilting  forward 
of  the  second  bicuspid.  The  abscessed  root  here  shown  was  ex- 
tracted.^ Fig.  239  illustrates  the  appearance  of  two  molars,  the 
posterior  half  of  one  of  which  is  destroyed,  showing  also  the  ap- 

^Driifal  Cusinus,  vol.   xxvi,  No.  3. 


124 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


plication  of  two  cap-crowns,  whicli  are  constructed  so  as  to  form 
a  cantilever  bridge  over  the  chasm  by  locking  midway  in  such 
a  manner  as  to  prevent  tilting  or  sliding  of  surfaces,  and  at  the 
same  time  be  easily  cleansed  by  a  quill  or  thread. 

METHODS   OF   CROWNING   IN   CASES   OF    IRREGULARITY. 

Pig.  240.  Fig.  240  shows  a  method  of  treat- 

ing a  case  of  irregularity  without  de- 
strojdng  the  vitality  of  the  pulp.  The 
tooth  at  B,  which  stood  inside  the  line 
of  the  lower  teeth  when  the  mouth 
was  closed,  was  trimmed,  shaped,  and 
capped.  To  this  cap  was  attached 
the  tooth  at  A,  with  an  oval-shaped 
piece  of  gold  that  cleared  the  lower 
teeth  in  occlusion.  The  cap  was  then 
cemented  to  the  natural  crown. 
Fig.  241  represents  a  case  of  irregularity  treated  by  Dr.  Bon- 
will,  who  says  in  his  description  of  it, — 

"This  shows  a  case  of  irregularity  which  was  beyond  correc- 
tion, on  account  of  the  poor  character  of  the  teeth,  their  position 
in  the  palatal  arch,  and  the  age  of  the  patient.     In  such  cases  I 

Fig.  241. 


do  not  hesitate  to  cut  off  the  crown,  destroy  the  pulp,  and  insert 
an  artificial  crown.  The  crown  is  brought  in  the  circle  and  con- 
nected with  the  root  by  a  strip  of  heavy  gold  plate.  The  plate 
is  attached  to  the  root  with  a  post  or  a  screw  with  a  nut." 


CHAPTER    XI. 

PAKTIAL  CROWNS. 

All-Gold. — Partial  crowns  of  gold  for  the  protection  of  plastic 
fillings  in  large  cavities  and  for  the  restoration  of  contour  are 
often  desirable  when,  for  any  reason,  a  solid  metallic  filling  cannot 
well  be  inserted.  The  cavity  having  been  properly  excavated, 
its  orifice  is  trimmed  as  uniformly  straight  or  circular  as  its  posi- 
tion and  character  will  allow,  and  the  edge  of  the  enamel  beveled 
off,  tapering  toward  the  center.  Deep  or  extensive  undercuts  may 
be  filled  with  oxyphosphate.  In  the  preparation  of  cavities  in 
the  grinding-surface,  trimming  and  cutting  away  the  enamel 
sliould  be  confined  to  that  surface.  In  approximal  cavities  which 
reach  the  grinding-surface,  it  is  advisable  to  extend  them  into  that 
surface  and  bring  the  gold  over  and  anchor  it  there,  so 
as  to  afford  greater  security  against  its  displacement  in 
mastication.  "Where  decay  extends  close  to  the  mar- 
gin of  the  gum,  if  the  tooth  is  trimmed  away  so  that 
the  gold  will  extend  just  under  its  free  edge,  a  recur- 
rence of  decay  at  that  point  will  be  avoided.  The  bi- 
cuspid shown  in  Fig.  242  will  serve  as  a  typical  case  to  illustrate 
the  constructive  details. 

The  cavity  having  been  properly  prepared,  a  die  of  the  tooth 
in  its  original  form  is  then  secured.  For  this  purpose  the  mold  is 
made  by  taking  an  impression  of  the  tooth  with  wax  or  impression 
compound,  making  a  plaster  model,  and  then  restoring  the  con- 
tour and  forming  from  it  the  mold  in  gutta-percha  or  moldine; 
or  the  shape  of  the  natural  tooth  may  be  restored  with  wax  or 
gutta-percha  and  the  mold  made  directly  from  it  in  plaster.  The 
die  and  counter-die  having  been  formed  (see  article  on  "Molds  and 
Dies"),  a  piece  of  pure  gold,  ISTo.  28  to  30  standard  gauge,  the 
exact  thickness  being  governed  by  the  size  and  nature  of  the  cavity, 
is  struck  up  to  the  form  and  size  of  the  part  to  be  capped.     The 

125 


126 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  243. 


Fig.  244. 


gold  is  then  adjusted  to  the  cavity,  to  the  margin  of  which  the- 
edges  are  trimmed  and  burnished  to  fit  close  and  flush.  In  th& 
case  of  large  cavities  including  a  part  or  the  whole  of  the  approxi- 
mal  surface,  a  plaster  model  of  the  tooth  and  of  the  empty  cavity 
from  an  impression  taken  in  wax  or  impression  compound  will 
facilitate  and  guide  the  preliminary  trimming  and  shaping  of  the 
gold.  Two  headed  pins  fixed  on  the  inside  of  the  cap  (Fig.  243) 
are  usually  sufficient  to  secure  it,  but  others  can  be 
added  if  the  conditions  of  the  case  seem  to  require 
it.  In  compound  cavities,  including  one  side  and 
the  grinding-surf  ace,  one  pin  at  least  should  be  fixed 
in  the  latter  portion.  Where  the  grinding  and 
both  approximal  surfaces  are  included,  a  wire 
should  be  extended  from  one  side  to  the  other 
(Fig.  244),  but  the  brace  should  not  touch  the  bot- 
tom of  the  cavity. 

In  pulpless  teeth  the  pin  from  the  upper  part  of 
the  cap  should  extend  up  the  canal,  which  gives 
great  stability  in  such  cases  (Fig.  245). 

In  soldering  the  pins  or  loops  when  inserted  in 
holes  drilled  in  the  gold,  a  little  solder  can  be  flowed 
over  the  adjacent  parts  if  deemed  necessary  to 
stiffen  and  strengthen  them. 

Oxyphosphate,  as  a  rule,  is  preferably  used  for 
the  cementation  of  these  caps,  as  it  forms  a  solid 
and  unyielding  foundation,  and,  when  properly  pro- 
tected from  the  fluids  of  the  mouth  by  a  carefully 
adjusted  cap,  is  very  durable. 

The  cement  should  be  first  inserted  in  the  cavity, 
and  then  a  small  quantity  placed  around  the  pins  of  the  cap,  which 
should  be  immediately  adjusted  accurately  in  position.  When 
gutta-percha  is  used,  it  is  heated  and  applied  in  the  same  manner 
to  cavity  and  cap.  The  cap  is  then  heated,  pressed  into  position, 
and  held  there  until  the  gutta-percha  hardens.  This  can  be 
hastened  by  the  application  of  cold  water  from  a  syringe.  The 
surplus  of  gutta-percha  is  then  removed,  and  the  edges  of  the  gold, 
burnished. 

These  caps  applied  to  teeth  with  living  pulps  show  durability 
of  a  commendable  character.     The  advantage  they  possess  over 


Fig.  245. 


PARTIAL  CROWNS.  127 

pieces  of  porcelain  is  found  in  the  close  joint  that  can  be  made 
with  the  edge  of  the  enamel  by  burnishing  the  gold  against  it. 

Solid  Gold  Inlays. — The  walls  of  at  least  the  aperture  of  the 
cavity  are  trimmed  straight,  'No.  60  platinum  foil  is  adapted  to 
the  interior  of  the  cavity  and  just  over  its  edges  by  the  aid  of 
burnishers  and  cotton  twisted  on  the  end  of  an  instrument,  assisted 
by  frequent  annealing  of  the  platinum.  The  matrix  thus  formed 
is  then  filled  witli  wax,  chilled,  and  removed  from  the  cavity  and 
invested,  after  which  fine  gold  or  22-carat  solder  is  melted  into  it. 
The  removal  of  the  matrix  from  the  cavity  can  be  facilitated  by 
the  insertion  in  the  wax  of  a  pin  or  a  short  piece  of  wax,  which  is 
grasped  with  tweezers.  The  plug  of  gold  thus  formed  is  properly 
trimmed  and  polished,  and  cemented  in  the  cavity  of  the  tooth. 
When  completed,  it  has  the  appearance  of  a  gold  filling.  If 
necessary,  the  cavity  must  be  previously  partly  filled  with  oxyphos- 
phate  or  amalgam  or  shaped  with  it,  to  give  a  better  form  to  per- 
mit the  removal  of  the  shell  of  platinum  foil.  Plugs  so  made  can 
occasionally  be  utilized  as  an  anchorage  for  bridge-work. 

Gold  Inlays  with  Extensive  Restoration  of  Contour. — Dr.  W. 
V-B.  Ames's  method  for  approximal  cavities  in  molars  and  bi- 
cuspids is  as  follows:  After  preparing  the  cavity  as  has  already 
been  described,  an  impression  is  taken  in  impression  compound  and 
a  plaster  model  made.  A  piece  of  ISFo.  36  gauge  24-carat  gold  is 
shaped  first  to  the  cavity  on  the  model  and  then  to  the  tooth  in  the 
mouth.     The  gold  is  depressed  into  Pig   246. 

any  anchorage  cavity  that  has  been 
secured  at  the  occluding  surface. 
To  fill  this  gold  matrix  22-carat  sol- 
der is  used.  For  instance,  in  a  case 
such  as  is  illustrated  in  Fig.  246,  a 
little  of  the  solder  is  first  melted  in 
the    most    depressed    or    anchorage 

cavity  of  the  occluding  surface,  by  holding  the  matrix  in  a  Bunsen 
flame.  The  matrix  is  again  fitted  to  the  cavity  and  the  operation 
of  fitting  and  soldering  continued  until  the  required  contour  is 
obtained.  To  facilitate  the  contouring  it  is  well  to  tack  at  the 
proper  point  a  small  globule  of  high-grade  solder  as  shown  at  A. 
To  and  around  this  globule  pack  crystal  gold  or  foil  to  the  line  or 
bulge  of  the  required  contour,  and  flow  solder  in  the  interstices^ 


128  ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 

shaping  the  rest  of  the  inlay  at  the  same  time.     If  considered 
necessary,  the  matrix  may  be  invested  for  this  final  soldering. 

8olid  Gold  Tips  for  Abraded  Pulpless  Front  Teeth  in  prefer- 
ence to  fillings  are  constructed  in  the  following  manner:  An  open- 
ing is  made  through  the  occluding  surface  of  the  crown  into  the 
root-canal.  A  flat  post,  wide  enough  to  fit  closely  in  the  pulp- 
chaml)er  across  its  greatest  diameter,  thus  tending  to  prevent  any 
rotary  motion  of  the  gold  tip,  is  then  formed.  A 
Fig.  24 <.  y^^^j  ^j^^^^  piece  of  pure  gold  plate,  say  ISTo.  30 

LT.  S.  gauge,  is  adapted  and  burnished,  with 
hand-burnishers  and  Herbst's  revolving  agate 
points,  into  all  the  irregularities  of  the  abraded 
surface,  and  into  the  orifice  of  the  pulp-cham- 
ber. The  gold  is  then  trimmed  flush  and  even 
to  the  edges,  and  burnished  just  over  them. 
An  opening  is  next  made  in  this  gold  cap,  and  through  it  the 
post  is  inserted  in  position,  fastened  with  wax,  removed  and  sol- 
dered to  the  cap.  The  post  and  cap  are  inserted  in  position  and 
the  gold  again  burnished  to  the  edges  of  the  tooth  and  trimmed 
closely.  Wax  cement  is  then  placed  on  the  gold  and  shaped  to 
the  exact  form  of  the  required  gold  tip.  This  is  next  encircled 
with  a  strip  of  'No.  60  gold  foil  fitted  against  the  surface  of  the 
wax  and  extending  slightly  over  on  the  surface  of  the  enamel  of 
the  tooth.  This  foil  is  to  form  a  matrix.  All  is  now  removed  and 
invested  in  finely  calcined  marble-du"st  and  plaster  (see  Fig.  247). 
Pig.  248.  '^'^^^  investment  is  next  heated,  and  20-carat  gold  solder 
melted  into  the  matrix  formed  by  the  foil  over  the  cap. 
The  surplus  gold  is  then  trimmed  to  the  edge  of  the 
abraded  surface  of  the  tooth  and  to  the  desired  form  for 
the  tip,  and  polished.  The  trimming  or  polishing  of  that 
portion  of  the  tip  at  or  adjacent  to  the  edge  which  fits 
against  the  tooth  should  always  be  done  with  the  tip  in 
position  on  the  tooth.  When  finished,  the  gold  tip  is 
cemented  in  position  with  a  thin  mixture  of  oxyphosphate.  Fig. 
248  gives  a  sectional  view  of  a  central  incisor  tipped  in  this  manner. 
For  Gold  Tips  in  Cases  of  Living  Pidps,  two  or  three  small 
platinum  pins,  as  the  case  may  suggest,  are  used  in  holes  drilled 
about  the  pulp-chamber,  in  the  manner  shown  in  Fig.  249.  Three 
pins  are  generally  placed  in  upper  incisors  and  two  in  lower  inci- 


PARTIAL  CROWNS. 


129 


Fio.  249. 


sors.      Three  pins  should  always  be  used  except  in  very  small  lower 

incisors  where  the  space  will  not  permit  more  than  two.     The  pins 

should  be  inserted  and  soldered  in  the  gold  plate  one  at  a  time, 

the  plate  each  time  being  adjusted  to  the  surface  of  the  tooth. 

The  first  pin,  if  fitted  tightly  in  the  hole 

through  the  gold,  can  be  soldered  without 

investing,    l)ut    an    investment    should    be 

made  for  the  soldering  of  each  subsequent 

pin,  as  otherwise  the  previously  soldered 

l^in  or  pins  are  apt  to  move  from  position. 

The  least  possible  quantity  of  solder  should 

be  used  on  the  first  two  pins.     After  all  the 

pins  have  been  soldered  in  position  to  the 

gold  cap,  it  is  adjusted  on  the  tooth  and  the 

gold  very  carefully  biu-nished  to  its  surface   and  trimmed.      A 

final  investment  is  then  made  and  the  required  form  of  the  incisive 

edge  added  with  solder. 

In  a  case  with  a  vital  pulp,  or  in  a  pulpless  tooth  if  the  gold 
tip  required  is  short,  the  ends  of  the  pins  extending  above  the 
cap  will  hold  and  maintain  enough  solder  in  position  to  give 
material  for  proper  contouring,  without  enveloping  the  wax  with  a 
matrix  of  gold  foil  as  previously  described.  If  three  pins  are  used,. 
it  is  very  seldom  necessary  for  stability  to  extend  the  plate  beyond 
the  incisive  surface,  over  the  palatal  side  of  the  tooth. 

The  partial  restoration  in  gold  of  a  crown  having  a  vital  pulp 
by  the  methods  explained  is  illustrated  in  detail  by  Fig.  250,^ 
which  illustrates  the 
partial  restoration 
of  a  central  incisor 
and  molar  with  vital 
pulps.  The  gold  for 
the  incisor,  it  will  be 
seen,  is  adapted  to 
the  palatal  surface 
and  supported  by 
three  pins. 

1  An  experience  of  several  years  in  the  use  of  gold  tips  as  described  shows  that 
they  are  much  to  be  prefen-ed  to  tips  formed  of  gold  foil,  even  by  the  very  best 
operators,  the  alloyed  gold  being  superior  to  pure  gold  in  resisting  attrition  — G.  E 

10 


Fig.  250. 


130 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  251. 


Fig.  251  shows  the  details  of  a  restoration  cast  filling  for  a 
molar.  The  contour  of  the  part  to  be  restored  was  shaped  in  wax 
on  the  cap  and  pins.  The  wax  was  covered  with  No.  60  gold 
foil  except  at  one  end,  and  invested  in  the  form  of  a  matrix  as 
shown  at  A,  and  in  section  at  B.     The  wax  was  removed  from 

the    matrix    with 
boiling  water 

through  the  open 
end,  and  the  ma- 
trix was  heated 
and  properly  filled 
with  gold  solder 
through  the  same 
opening.  Anoth- 
er method  is  to 
strike  up  a  grinding-surface  of  pure  gold  of  about  No.  34  gauge, 
adjust  on  the  cap  with  wax,  fit  in  the  mouth  to  determine  oc- 
clusion, remove,  invest,  and  fill  the  cavity  through  the  opening 
with  solder. 

Porcelain  and  Gold. — The  partial  restoration  with  porcelain 
:and  gold  of  an  incisor  crown  such  as  is  shown  in  Fig.  252  can  be 
accomplished  as  here  described:  The  edges  of  the  crown  to  form 
the  joining  with  the  porcelain  are  trimmed  straight  and  level,  and 


Fig.  252. 


Fig.  253. 


Fig.  254. 


C-' 


then  polished.  A  shallow  groove  is  generally  formed  to  advan- 
tage at  A,  Fig.  253.  A  very  thin  piece  of  platinum  is  then 
adapted  to  the  crown  as  shown  at  B,  Fig.  254.  The  pin  C  is  fitted 
to  the  root-canal,  passing  through  the  platinum.  The  post  and 
cap  of  platinum  are  then  attached  with  wax,  removed,  invested, 
and  soldered  with  pure  gold.  A  little  of  the  gold  at  the  same  time 
is  fiowed  over  the  cap.     The  cap  and  post  are  then  adjusted  to  the 


PARTIAL  CROWNS. 


131 


crown,  and  the  cap  is  trimmed  level  and  burnished  closely  against 
the  surface  of  the  portion  to  be  restored  and  into  the  groove  at  A, 
Fig.  253.  At  this  stage  of  the  work,  to  facilitate  the  subsequent 
operations,  an  impression  can  be  taken  which  will  remove  in  it 
the  cap,  and  from  this  a  model  can  be  made.  A  cross-pin  porce- 
lain tooth  is  then  ground  down  to  a  size  and  shape  that  will  prop- 
erly restore  the  part  and  form  an  accurate  joint  with  the  labial  edge 
of  the  natural  crown.  The  porcelain  ig  then  backed,  cemented  to 
the  cap,  removed,  and  soldered  with  20-carat  solder.  The  partial 
crown  when  properly  finished  is  cemented  in  position  with  oxv- 
phosphate. 


Fig.  255. 


Fifi.  256. 


Fig.  257. 


In  a  case  such  as  is  represented  in  Fig.  255  the  cap  is  shaped 
to  the  surface  of  the  dentin  and  enamel  at  A,  and  over  its  palatal 
edge,  and  the  backing  on  the  porcelain  is  extended  out  over  the 
palatal  edges  of  the  enamel  at  B.  The  two  sections  of  the  plati- 
num are  united  in  the  soldering. 

Fig.  256  illustrates  a  fractured  central  incisor  in  which  the 
pulp  was  not  exposed,  restored  with  porcelain  by  Dr.  J.  Bond 
Littig.  The  cap  to  the  fractured  part  was  fastened  by  three  small 
pins  as  shown  in  Fig.  257,  which  illustrates  the  details  of  the  con- 
struction. 

"Where  the  piece  broken  off  is  so  narrow  that  the  porcelain 
tooth  cannot  be  ground  to  fit  in  the  ordinary  way,  without  cut- 
ting out  the  pins,"  Dr.  Littig  describes  his  method  as  follows: 
"First  cut  a  groove  in  the  end  of  the  broken  tooth,  making  slight 
undercuts.  The  pins  of  a  suitable  porcelain  tooth  are  bent  out- 
ward, and  the  ends  flattened.  The  porcelain  is  then  ground  away 
from  both  ends,  until  it  is  made  as  narrow  as  the  natural  tooth  is 


132 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


thick  or  nearly  so.  The  piece  is  fitted  to  the  end  of  the  tooth  by 
placing  the  pins  in  the  groove.  If  the  joint  is  not  good,  grind 
away  from  either  tooth  or  porcelain  nntil  it  is  perfect.  Then  set 
the  piece  with  zinc  phosphate,  and  after  it  has  become  hard,  grind 


Fig.  258. 


Fig.  259. 


Fig.  260. 


the  tip  to  shape  in  the  month,  and  polish  with  moosehide  disk  and 
pnmice-stone.  Fig.  258  illnstrates  the  second  method;  the  gronnd 
porcelain  tip,  prepared  crown,  and  restored  tooth  being  shown 
separately."-^ 

Figs.  259  and  260  illnstrate  a  case  in  which  the  contour  of  an 
incisor  tooth  was  restored  by  Dr.  W.  F.  Litch's  pin-and-plate  pro- 
cess. Fig.  259  shows  the  palatal  as- 
pect of  the  tooth,  in  which  the  open- 
ings for  two  retaining  pins  were 
drilled,  the  openings  being  made  quite 
small.  In  Fig.  260  is  seen  the  por- 
celain tip  attached  to  the  plate  and 
ready  for  mounting.  The  two  retain- 
ing-pins  will  be  observed  soldered  to  the  plate.  In  this  case  the 
cervical  margin  of  the  natural  tooth  was  made  level  to  afford  a 
secure  resting-place  for  the  porcelain  tip. 

1  The  partial  restoration  of  teeth  with  porcelain  is  explained  in  the  chapter  on 
"Porcelain  Dental  Art." 


CIIAPTEK    XII. 

FINISHING  AND  POLISHING— PROCESS  OF  CEMENTATION. 
FINISHING   AND   POLISHING    CROWN-WORK. 

The  finishing  should  be  done  with  small  corundum  or  Gem 
wheels  and  points,  first  coarse,  then  fine,  on  the  dental  engine, 
which,  for  this  part  of  the  work,  is  preferable  to  files  or  the 
lathe.  Gem  wheels  may  be  used  dry  when  desired.  This  is  an 
advantage  in  trimming  certain  parts  of  the  metal,  as  corundum 
must  be  kept  wet.  In  the  final  finishing  use  fine  pumice  with 
leather  polishing-wheels  on  the  engine,  or  felt  wheels  on  the 
lathe;  and,  in  the  polishing,  a  brush  wheel,  with  whiting  and 
rouge  on  the  lathe. 

The  gold  should  first  be  properly  shaped,  which  includes  trim- 
ming the  collar  off  to  a  fine  edge  where  it  fits  under  the  gum, 
so  that  the  seam  of  the  union  with  the  root  will  be  imperceptible. 
The  gold  that  has  been  placed  on  the  incisive  edge  of  the  incisor 
and  cuspid  crowns  should  be  trimmed  away,  so  that  although 
it  will  protect  the  porcelain,  very  little  if  any  gold  will  be  seen 
when  the  crown  is  in  position  in  the  mouth. 

INSERTION    AND   CEMENTATION. 

In  the  insertion  and  cementation  of  all  crown-  and  bridge- 
work,  the  object  to  be  effected  is  the  same  in  principle,  that  is, 
to  form  with  an  insoluble  material  a  solid,  substantial,  and  im- 
pervious union  l>etween  the  natural  tooth  or  root  presented  and 
the  artificial  crown. 

OXYPHOSPHATE   OF  ZINC. 

As  a  cement  for  this  purpose,  the  plastic  oxyphosphate  of  zinc 
is  generally  preferred,  and  it  is  in  many  respects  one  of  the  most 
suitable  that  has  as  yet  been  found.  If  at  all  exposed  even  the 
best  preparations  are  slowly  soluble  in  the  mouth,  and  the  porosity 
of  the  compound  permits  it  to  absorb  gases  and  fluids  and  gradually 
become  septic.  Exact  scientific  proportions  of  the  chemical  sub- 
stances of  which  the  cement  is  composed  are  essential  in  its  prep- 

133 


134  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

aration.  The  oxid  of  zinc  should  have  been  calcined  at  a  high 
beat,  and  then  ground  to  a  very  fine  powder.  It  should  possess 
the  property  of  being  uniformly  dense  and  hard  clear  through 
the  center,  when  set,  after  being  mixed  thin  and  formed  in  a  mass. 
The  density  of  one  preparation  of  oxyphosphate  of  zinc  in  com- 
parison with  another  can  be  tested  by  placing  samples  of  each  of 
the  same  size,  mixed  under  similar  conditions,  in  red  ink.  After 
immersion  for  one  or  more  weeks  the  samples  can  be  removed, 
washed,  then  cut  through  the  center,  and  their  comparative  density 
determined  approximately  by  the  depth  of  the  stain. 

The  setting  of  the  best  preparations  of  pure  oxyphosphate  of 
zinc  is  materially  affected  by  temperature.  Thus,  a  cement  which 
is  slow-setting  at  40°  F.  is  apt  to  be  quite  quick-setting  at  80°  F. 
In  some  of  the  preparations  of  cement,  an  effort  is  made  to  remedy 
this  variation  by  adulterating  with  various  substances,  but  this 
tends  to  increase  the  solubility  of  the  compound.  A  standard 
preparation  of  cement,  answering  the  requirements  previously 
outlined,  should  be  used  in  crown-  and  bridge-work.  For  all 
styles  of  crowns  with  collars,  and  for  bridge-work  depending  on 
crowns  of  similar  construction,  the  cement  should  be  mixed  thin; 
but  for  crowns  without  a  ferrule  or  collar  it  can  be  moderately 
thick.  For  mixing  the  cement,  a  piece  of  plate-glass  about  five 
inches  long  and  three  inches  wide  as  a  slab,  and  a  small  spatula, 
are  suitable.  The  surface  of  the  slab  must  be  perfectly  clean. 
The  acid  and  powder  should  first  be  separately  placed  on  the  glass, 
the  amount  of  powder  being  fully  equal  to  the  requirements  of 
the  acid.  A  portion  of  the  powder  should  be  drawn  over  and 
mixed  with  the  acid,  and  then  more  of  the  powder  added,  a  little 
at  a  time,  until  a  suitable  consistence  is  reached,  when  the  surplus 
powder  should  be  instantly  thrown  off  the  slab,  and  the  mixing, 
which  must  be  rapid  and  thorough,  continued;  the  consistence 
should  be  that  of  thick  cream.  It  is  not  a  good  plan  to  mix 
cement  excessively  thin,  and  then  wait  until  it  becomes  thick- 
ened by  the  process  of  setting  to  a  consistence  suitable  for  use. 
The  resulting  compound  is  unnecessarily  acid,  the  overplus  of 
acidity  being  proportioned  to  the  excess  of  acid  used  over  the 
quantity  required,  and  its  character  as  a  cement  impaired.  On 
the  other  hand,  if  mixed  too  thick,  force  is  required  to  bring  the 
crown  or  cap  to  position,  and  the  thin  edges  of  collars  are  liable  to 


INSERTION  AND  CEMENTATION.  135 

be  sprung  from  the  sides  of  the  roots;  neither  will  the  cement  ad- 
here with  such  tenacity  to  the  parts  as  when  mixed  at  a  proper 
consistence.  If  the  slab  is  placed  on  a  towel  which  has  been 
saturated  with  ice-water,  the  cold  will  retard  the  setting,  which 
is  quite  an  advantage  in  many  cases.  In  this  respect  the  side  of 
a  square  bottle  filled  with  ice-water  and  well  corked  is  preferable 
to  a  slab. 

The  parts  to  be  crowned  should  be  previously  syringed  with 
water  and  peroxid  of  hydrogen  if  the  gum-margins  are  slightly 
lacerated,  then  protected  by  a  napkin,  bathed  with  alcohol  ap- 
plied on  cotton  with  tweezers,  and  dried  with  absorbent  cotton  or 
bibulous  paper.  A  rope  of  twisted  absorbent  cotton  may  be 
wound  around  each  natural  crown  and  pressed  close  against  the 
gum,  with  the  ends  twisted  together  at  the  labial  side  so  that 
the  cotton  can  be  easily  seized  and  instantly  removed  at  the 
moment  the  cement  is  ready.  Each  cap  or  crown,  which  should 
have  been  thoroughly  dried,  is  first  filled  with  enough  cement 
to  insure  a  slight  surplus.  A  small  portion  is  then  put  in  each 
root-canal  or  hollow  part  of  a  natural  crown  present,  and  the 
artificial  crown  or  bridge  immediately  adjusted  in  position.  In 
many  cases  it  is  best  to  quickly  remove  the  napkin  and  close 

Fig.  261. 


the  mouth  to  insure  the  occlusion  of  the  teeth,  and  then  open 
the  mouth  and  replace  the  napkin.  The  crown  or  bridge  should 
be  held  under  a  slight  pressure  until  the  cement  has  set.  For 
this  purpose  a  piece  of  wood  notched  on  the  end,  or  a  crown- 
driver^  (Fig.  261),  can  be  used.  With  bicuspids  or  molar  crowns 
and  in  bridge-work,  however,  it  is  better  in  most  cases  to  occlude 
the  teeth,  and  keep  them  in  position  under  a  steady  pressure  until 

1  This  instrument  can  be  used  to  fit  a  tight  collar  or  crown.     It  also  has  a  pull- 
off  attachment  which  is  handy  in  removing  crowns. 


136  ARTIFICIAL  CliOWN-  AND  BRIDGE- WORK. 

the  cement  sets.  Under  tliese  cireniustances  the  saliva  can  reach 
only  the  snrplns  portion  of  the  cement,  and  cannot  interfere  with 
that  nnder  the  cap  or  crown.  One  or  two  thicknesses  of  tin  foil, 
placed  over  the  crown  as  the  teeth  are  occlnded,  will  slightly  favor 
the  length. 

When  the  cement  has  set  perfectly  hard,  the  snrplns  around 
the  edges  should  he  removed.  In  collar  or  shell  crowns  the  ex- 
treme edges  of  the  gold  of  the  collar  or  shell  should  he  given  a 
tinal  burnishing.  Excessive  burnishing  and  force,  though,  should 
he  avoided,  as  tending  to  injure  the  cement  under  the  collar.  Wet 
floss  silk  or  dental  fiber,  charged  ^vith  pumice,  should  be  passed 
between  and  around  the  teeth  to  remove  every  particle  of  the 
superfluous  cement,  and  Anally  the  parts  should  be  syringed  with 
tepid  water. 

The  patient  should  be  requested  to  call  in  a  few  days,  so  tliat 
an  examination  may  he  made  to  see  if  any  particles  of  the  cement 
were  overlooked.  C'leansing  gently  at  this  time  facilitates  the 
healing  of  the  gmu  around  the  collar  or  neck.  Care  in  these 
little  details  tends  to  prevent  that  inflamed  appearance  and  reces- 
sion of  the  gum  often  seen  around  crowns,  and  also  insures  a 
satisfactory  result  to  the  patient  and  commendation  to  the  dentist. 

Previous  to  insertion  the  posts  of  cro^^^lS  should  be  slightly 
barbed.  By  encasing  the  post  with  a  fllm  of  gutta-percha  it  is 
made  easily  removable,  whicli  is  a  desirable  feature  in  crown- 
or  bridge-work.  This  is  done  by  warming  the  crown  to  a  point 
that  will  heat  the  post,  and  then  painting  the  post  with  a  thin 
coat  of  chloro-percha.  The  heat  instantly  evaporates  the  chloro- 
form, leaving  a  thin  fllm  of  warm  gutta-percha  adhering  to  the 
post.  The  crown  is  then  instantly  placed  on  the  root  and  re- 
moved. This  deflnes  the  relations  of  the  gutta-percha  on  the 
post  to  the  walls  of  the  canal,  and  indicates  any  slight  surplus 
if  present.  Cementation  with  the  oxyphosphate  completes  the 
operation.  At  any  time,  by  warming  the  crown,  the  thin  sheath 
of  gutta-percha  is  softened  and  the  attachment  of  the  post  inay 
be  easily  broken.  This  method  of  setting  the  post  makes  bridge- 
work,  so  supported,  easily  detachable.  A -fllm  of  gutta-percha 
placed  in  the  grinding-surface  of  a  gold  ca]>  will  also  provide  a 
similar  advantage  in  case  of  a  gold  crown.  The  gold  cap  should 
be  fii'st  heated,  the  gutta-percha  inserted,  and  the  cap  adjusted  and 


INSERTION  AND  CEMENTATION. 


137 


removed  and  the  amount  and  position  of  gutta-percha  exactly 
determined.    Th6  cementation  is  then  y\o.  262 

■conducted  as  without  the  gutta- 
percha. In  all-gold  cap-crowns  a  vent 
for  the  escape  of  air  and  surplus  ce- 
ment is  made  by  some  in  the  form 
■of  a  small  hole,  usually  in  the  deepest 
fissure  of  the  grinding-surface,  but  it 
is  a  practice  that  is  now  being  gen- 
erally discarded.  When  the  cement 
has  hardened,  the  hole  must  in  all 
cases  bo  closed  with  a  gold  or  amal- 
gam filling. 


GUTTA-PERCHA. 

The  merits. of  gutta-percha  for  the 
cementation  of  crown-  and  bridge- 
work  are:  Gutta-percha  is  insoluble  in 
the  fluids  of  the  mouth,  but  at  any 
time  the  work  can  be  removed  by 
the  application  of  suflicient  heat  to 
soften  it.  To  be  able  to  remove  work 
thus  easily  is  an  advantage  that  is  ap- 
parent without  comment.  In  com- 
parison with  oxyphosphate,  it  lacks 
rigidity,  so  that  its  sphere  of  applica- 
tion is  limited,  and  there  are  besides 
the  well-known  difficulties  which  at- 
tend its  manipulation. 

Ci'owns  without  Collars. — When 
gutta-percha  is  used,  heat  the  crown. 
Paint  the  post  and  the  base  of  the 
crown,  and  any  recesses  in  the  latter, 
with  a  very  thin  solution  of  chloro- 
gutta-percha.  The  heat  instantly 
evaporates  the  chloroform,  leaving  a 
mere  film  of  gutta-percha  tenaciously 
adhering  to  the  parts.     Fill  the  recess  and  cover  the  base 


138  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

crown  with  a  perforated  disk  of  gutta-percha,  and  press  the  crown- 
to  position  on  the  root.  Let  the  gutta-percha  cool  slightly,  re- 
move the  crown  and  trim  the  surplus  from  the  edges;  wipe  out 
the  canal  with  chloroform,  dry  with  cotton  and  hot-air  syringe. 
J^ext  place  on  the  post  or  in  the  canal  enough  gutta-percha  to- 
insure  a  very  slight  surplus,  heat  the  crown,  and  press  to  place. 

A  crown-setter,  as  illustrated  in  Fig.  262,  heats  the  crown  and 
assists  in  setting  with  gutta-percha.  Heat  the  copper  end  suf- 
ficiently to  soften  the  gutta-percha,  and  place  the  grooved  end  over 
the  crown  with  the  heated  copper  in  contact  with  the  porcelain. 
Hold  the  setter  against  the  crown  until  the  gutta-percha  becomes 
soft,  when  pressure  applied  to  the  setter  forces  the  crown  with  its 
pin  to  its  proper  position.  The  cooling  of  the  gutta-percha  can 
be  hastened  by  dipping  the  crown-setter  in  a  tumbler  of  ice- 
water  and  holding  it  against  the  tooth  until  it  is  cold.  When 
the  gutta-percha  is  cold,  the  surplus  is  removed  with  a  warmed 
sharp  instrument,  and  the  edges  smoothed  by  drawing  back  and 
forth  against  them  some  twisted  fibers  of  cotton  or  floss  silk  sat- 
urated with  chloroform.  Sometimes  it  may  be  desirable  to  fasten 
the  post  with  oxyphosphate  and  join  the  end  of  the  root  and  ar- 
tificial crown  with  gutta-percha.  In  such  a  case  the  crown  should 
be  heated  and  the  gutta-percha,  rolled  down  very  thin,  placed  on 
the  edges  to  be  united  in  the  form  of  a  perforated  disk.  The 
crown  is  then  pressed  to  position  in  the  oxyphosphate  placed  in 
the  root.  The  order  of  the  use  of  these  materials  should  be  re- 
versed where  it  may  be  desirable  at  some  future  time  to  easily 
remove  the  crown. 

Collar  Crowns  with  or  without  Posts. — The  crown  is  heated,, 
freshly  prepared  chloro-gutta-percha  is  painted  all  over  the  in- 
side of  the  cap  and  over  any  post  present  in  successive  layers  as  the 
chloroform  evaporates.  The  quantity  of  gutta-percha  at  first  ap- 
plied should  be  a  little  less  than  will  be  required  to  properly  cement 
the  cap.  The  whole  crown  is  next  heated  to  a  point  sufiicient  to 
cause  the  gutta-percha  to  adhere  to  the  metal,  but  not  to  burn 
the  gutta-percha.  The  crown  is  allowed  to  cool  enough  to  permit 
it  to  be  handled  and  adjusted  in  position  on  the  tooth  or  root, 
and  then  instantly  removed  before  the  gutta-percha  cools.  The 
saliva  present  on  the  teeth  prevents  the  adhesion  of  the  gutta- 
percha to  the  tooth-structure.     The  inside   of  the  cap  is  next 


INSERTION  AND  CEMENTATION.  139 

washed  out  with  water,  followed  with  alcohol,  and  dried  with  a 
hot-air  syringe.  The  gutta-percha  on  the  inside  of  the  cap  will 
show  an  impression  of  the  natural  tooth  or  root.  Points  showing 
a  deficiency  of  gutta-percha  are  to  be  filled  up  with  more  of  the 
solution  in  chloroform,  or  it  may  be  well  to  use  a  little  of  the 
solid  gutta-percha  for  the  purpose.  The  crown  is  again  heated, 
adjusted  in  the  mouth,  and  removed,  this  being  repeated  until 
the  cap  shows  a  perfect  distribution  of  the  gutta-percha.  Any 
surplus  extending  from  the  edges  of  the  cap  should  be  removed. 

For  the  permanent  insertion  the  gutta-percha  is  dried  in  the 
same  manner  as  before.  The  tooth  or  root  is  protected  with 
napkins  and  also  dried,  and  then  varnished  with  an  exceed- 
ingly thin  solution  of  solidified  Canada  balsam  dissolved  in 
chloroform.  The  crown  is  next  heated  and  placed  on  the  tooth 
or  root  and  held  in  position,  either  with  an  instrument  or  by  oc- 
clusion of  the  teeth,  until  the  gutta-percha  cools.  There  is  usually 
very  little,  if  any,  surplus  to  remove.  If,  on  close  examination^ 
it  should  be  found  that  the  crown  has  failed  by  any  means  to 
exactly  assume  its  proper  position,  a  heated  crown-setter  or  the 
copper  bulb  of  a  root-canal  drier  may  be  applied,  and  the  crown 
heated  to  as  much  as  the  patient  can  bear,  which  will  soften  the 
attachment  to  allow  the  crown  to  be  pressed  to  place. 

As  to  the  amount  of  heat  that  can  be  tolerated  by  the  patient 
in  the  use  of  gutta-percha,  your  gauge  will  be :  Any  heated  crown 
or  bridge  that  can  be  held  by  the  fingers  of  the  operator  can 
always  be  inserted  without  special  discomfort  to  the  patient. 

Bridge-Worh, — The  method  of  cementing  on  a  single  crown  just 
described  can  also  be  well  applied  to  some  small  cases  of  bridge- 
work,  such  as  a  single  cap  with  an  extension  bridge  of  one  or  two 
teeth,  or  a  bridge  vdth  two  caps,  especially  if  all  or  nearly  all  of 
the  natural  crowns  of  the  abutment  teeth  are  present. 

Large  Pieces  of  Bridge-Work,  more  especially  where  the  caps 
cover  teeth  with  considerable  of  the  crov^nis  absent,  can  be  ce- 
mented with  gutta-percha  more  conveniently  by  the  following 
method:  Select  a  preparation  of  gutta-percha  which  softens  at  a 
low  heat.  Place  it  on  a  piece  of  soapstone  or  on  a  large  granite- 
ware  spoon.  Heat  up  until  the  gutta-percha  becomes  so  plastic 
that  it  can  be  worked  with  a  spatula.  Heat  the  bridge-work  and 
caps.     Coat  the  inside  of  the  caps  with  chloro-gutta-percha,  and 


140  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

when  the  chloroform  has  evaporated  place  the  giitta-percha  you 
have  heated  with  the  spatula  around  in  the  caps  somewhat  as  you 
would  oxyphosphate  cement.  Have  water  boiling  in  a  cup  and 
immerse  the  bridge  in  the  water,  letting  it  remain  for  about  one- 
half  minute.  Kemove  with  tweezers,  dry  the  exterior  with  a  nap- 
kin, and  immediately  adjust  in  the  mouth  in  position,  and  then 
quickly  remove  it.  On  removal,  the  gutta-percha  in  the  caps 
should  be  dried  as  described  in  the  use  of  chloro-gutta-percha,  and 
more  gutta-percha  added  where  required. 

The  boiling  and  insertion  are  repeated  until  a  proper  quantity 
of  gutta-percha  is  placed  in  each  cap.  The  gutta-percha  is  then 
again  dried,  and  the  caps  heated  in  a  flame  to  a  point  which  will 
assure  the  adhesion  of  the  gutta-percha  to  their  inner  surfaces. 
The  natural  crowns  or  roots  are  then  varnished  with  the  solution 
of  chloroform  and  Canada  balsam  as  before  described,  and  when 
the  bridge  is  at  a  heat  possible  to  handle,  it  is  permanently  placed 
in  position  in  the  mouth  and  cooled  with  ice-water  from  a  syringe. 
Should  the  bridge  be  found  to  have  failed  to  assume  its  proper 
position,  a  heated  crown-setter,  or  the  copper  bult  of  a  root-canal 
drier  from  which  the  point  has  been  removed,  can  be  applied 
rapidly  from  one  crown  to  another  until  a  heat  as  great  as  the 
patient  can  bear  is  reached,  when  the  caps  can  be  pressed  to  place. 

Another  method  of  heating  gold  crowns  in  the  mouth  is  to 
apply  a  gas  jet  about  one-eighth  of  an  inch  in  size  to  the  gold 
■caps.  This  is  done  by  passing  the  gas  through  a  small  brass  tube, 
like  the  nozzle  of  a  syringe,  connected  with  a  rubber  tube. 

Gutta-percha  and  OxypJiosphate  Comhined. — In  case  of  collar 
crowns,  envelop  the  post  with  gutta-percha  by  the  use  of  heat  and 
chloro-gutta-percha  as  described.  After  adjusting  in  the  mouth  re- 
move and  fill  the  cap  with  oxyphosphate  cement,  at  the  same  time 
placing  a  little  cement  on  the  post,  and  bring  the  crown  to  place 
on  the  root.  In  setting  gold  crowns  by  this  method,  apply  the 
gutta-percha  in  the  manner  described  for  gutta-percha  alone,  but 
in  a  slightly  less  quantity  than  is  required,  then  place  the  oxy- 
phosphate in  the  cap  or  caps  and  adjust  in  position  in  the  mouth. 

Crowns  and  bridges  mounted  in  this  manner  present  no  special 
difficulties  in  removal  when  desired;  for,  when  the  heat  applied  is 
sufficient  to  soften  the  gutta-percha  thoroughly,  the  oxyphosphate 
will  usually  loosen  sufficiently  to  permit  removal. 


INSERTION  AND  CEMENTATION.  141 

AMALGAM. 

Amalgam  is  used  to  some  extent  to  support  and  retain  porce- 
lain crowns.  Its  use  in  connection  with  the  Gates-Bonwill  crown 
is  given  on  page  48.  Where  it  is  desirable  to  use  amalgam,  Dr. 
Kirk  gives  copper  amalgam  the  preference  to  other  kinds  as  an 
attachment  for  the  Logan  crown  to  weak  or  badly-decajed  roots. 
The  following  is  Dr.  Kirk's  method  for  the  adjustment  of  Logan 
and  similar  classes  of  crowns,  which  he  has  found  satisfactory  in 
those  extreme  cases  where  there  has  been  much  loss  of  root-struc- 
ture through  the  action  oi,  caries  in  the  pulp-canal,  resulting  in 
a  large  funnel-shaped  opening  with  more  or  less  weakened  root- 
walls. 

The  canal  is  prepared  by  removing  the  softened  structure,  fill- 
ing the  apex,  and  making  suitable  undercuts  or  roughnesses  along 
its  walls,  and  then  filled  flush  with  its  orifice  with  a  good  grade 
of  copper  amalgam  softened  to  a  plastic,  buttery  condition.  The 
apical  end  of  the  crown  pin  is  sharpened  to  a  point  or  hatchet 
edge  as  may  be  most  expedient,  and  placed  against  the  amalgam 
surface  in  the  root-opening,  and  the  crown  at  once  driven  to  place 
in  close  contact  with  the  root  by  holding  against  its  morsal  (oc- 
cluding) surface  a  suitable  point  mounted  in  the  Bonwill  mechani- 
cal mallet.  For  this  purpose,  the  blow  of  the  mallet  should  be 
considerably  increased  in  intensity  beyond  that  ordinarily  used  for 
filling-operations.  The  point  used  in  the  mallet  for  driving  the 
crown  home  is  best  improvised  from  a  porte  polisher  armed  with 
a  hickory  point,  the  use  of  which  avoids  chipping  the  porce- 
lain. All  excess  of  copper  amalgam  is  by  this  means  driven  out 
between  the  surfaces  of  contact  of  the  crown  and  root  in  pre- 
cisely the  same  manner  as  occurs  in  the  use  of  oxyphosphate.  An 
excess  should  be  used  in  order  to  be  sure  of  filling  all  interstices. 
This  method,  involving  the  use  of  copper  amalgam,  is  advocated 
only  in  the  class  of  cases  described,  for  which  it  possesses  the  ad- 
vantage of  giving  complete  support  to  the  root,  because  of  the 
great  strength  and  insolubility  of  the  material  employed.  Other 
amalgams  experimented  with  for  this  purpose  have  not  been  so 
satisfactory,  because  of  their  lack  of  plasticity,  and  of  the  flowing 
quality  which  characterizes  the  coj)per  amalgam  when  subjected 
to  the  rapid  vibratory  percussive  force  of  the  mechanical  mallet 
blow. 


PAET  III. 


BRIDGE-WORK. 


BRIDGE-WORK. 

The  artificial  replacement  of  the  loss  of  a  portion  of  the  teeth 
by  bridging  the  vacant  spaces  with  substitutes,  supported  in  posi- 
tion by  means  of  their  attachment  to  adjoining  or  intervening 
natural  teeth,  is,  as  we  have  seen  in  the  introduction,  of  antique 
origin,  having  been  practiced  long  before  plates  came  into  use. 


Fig.  263. 


Fig.  264. 


Originally,  the  application  and  mechanical  construction  of  such 
dentures  was  of  a  most  primitive  character;  and  as  the  attach- 
ments were  simply  ligatures  or  clasps  of  gold,  the  teeth  were  more 
ornamental  than  useful.     Figs.  Fig.  265. 

263,  264,  and  265  illustrate  the 
antique  methods.^  Fig.  263  is 
an  illustration  of  a  specimen  of 
ancient  Phoenician  dentistry. 
Fig.  264  is  that  of  one  in  the 
Etruscan  age,  dating  about  five  hundred  years  b.c.  Fig.  265  gives 
a  view  of  the  same  denture  inverted. 

^  See  Independent  F7xictitioner,  vols,  vi  and  vii,  "Evidences  of  Prehistoric  Den- 
tistry," by  J.  G.  Van  Marter,  CDS.,  Eome,  Italy.  Figs.  263,  264,  265,  are 
copies  of  the  illustrations  of  the  specimens,  the  first  of  which  is  represented  as  being 
in  the  museum  of  the  Louvre,  Paris,  France,  and  the  second  in  the  Corneto 
Museum,  Corneto,  Italy. 

11  145 


146 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Dentures  constructed  on  the  bridging  plan  by  various  methods 
have  been  occasionally  employed  from  the  earliest  days  of  modern 
dentistry,  though  until  recent  years  the  system  has  not  obtained 
general  recognition  nor  been  extensively  practiced. 

Dental  literature  presents  bridging  operations  as  described  by 
J.  B.  Gariot  in  1805,  C.  F.  Delabarre  in  1820,  Dr.  S.  S.  Fitch  in 
1829,  William  Imrie  in  1834,  J.  Paterson  Clark  in  1836,  and 
Dr.  W.  H.  Dwindle  in  1856.  Figs.  266  and  267  are  copies  of 
illustrations  in  Dr.  Fitch's  work,  published  in  JSTew  York  in  1829, 
and  Fig.  268  one  from  a  translation  of  F.  Maury's  work  in  1843. 


Tig 

.  266. 

^ 

W^  ■?■"'! 

Fig. 

267. 

Fig.  268. 


Fig.  269. 
C    c     a.  a,   cc  o  c 


In  1871  the  bridging  process  or  bridge  principle  was  again  brought 
to  notice  by  a  patent  applied  for  in  England  by  Dr.  B.  J.  Bing,  of 
Paris,  for  an  improved  means  of  supporting  and  securing  a  bridge 
by  anchoring  with  cement  or  fillings  clasps  or  bars  extending  from 
it  into  holes  formed  in  the  adjoining  teeth  (Fig.  269).  The  sys- 
tem was  also  practiced  in  operations  by  the  late  Dr.  M.  H.  "Webb, 
and  is  described  in  his  "ISTotes  on  Operative  Dentistry." 

The  facilities  ajBForded  by  the  artificial   crown-work  now  in 
vogue  for  supporting  and  securing  bridge  dentures  have  caused 


BRIDGE-  WORK.  147 

a  revival  of  the  system  in  an  improved  form,  now  termed  "Bridge- 
Work,"  in  which  artificial  crowns  cemented  to  natural  teeth  or 
roots  are  employed  as  abutments  to  support  artificial  teeth  which 
span  or  bridge  the  spaces  between  them.  These  bridges  are  so 
devised,  in  the  best  methods,  that  while  supplying  the  patient  with 
the  means  of  masticating  his  food,  the  cleanliness  of  the  denture 
is  also  provided  for. 

Ordinarily,  bridge-work  is  immovably  cemented  in  position. 
The  claims  set  up  in  its  favor  are  as  follows : 

First.  The  perfect  replacement  of  lost  teeth  by  artificial  ones, 
and  without  the  use  of  a  plate. 

Second.  The  absence  of  any  mechanical  contrivance  to  inter- 
fere with  the  tongue  in  articulation. 

Third.  The  natural  teeth  are  not  abraded  by  the  presence  of 
clasps,  the  functions  of  the  sense  of  taste  are  more  perfectly  per- 
formed, and  a  healthy  condition  of  the  tissues  preserved,  because 
the  gums  and  palate  are  not  covered  over  with  a  plate. 

Fourth.  The  solidity  and  immovability  of  the  denture  at  all 
times,  both  in  speech  and  mastication. 

Fifth.  The  weight  of  the  denture  and  the  strain  of  mastica- 
tion are  proportionately  distributed  on  the  natural  teeth,  which 
are  better  suited  to  sustain  them  than  the  contiguous  alveolar  sur- 
faces. 

Sixth.  Its  special  adaptation  to  the  replacement  of  single  teeth, 
or  of  a  small  number,  where  bridge-work  is  usually  superior  to 
any  other  device. 

Seventh.  While  all  operations  performed  for  the  restoration 
of  lost  teeth,  like  other  remedial  operations,  are  temporary  rather 
than  permanent  in  their  results,  bridge-work  as  regards  perma- 
nency takes  equal  rank  with  any  other  operative  procedure. 

The  following,  on  the  other  hand,  are  the  objections  raised 
against  bridge-work: 

First.     It  fails  to  restore  the  contour  of  the  soft  tissues  above 


148  ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 

the  bridge,  as  artificial  gums  cannot  properly,  in  most  cases,  be 
used  in  this  style  of  work. 

Second.  The  slots  beveled  under  the  artificial  teeth,  called 
self -cleansing  spaces,  fill  with  particles  of  food. 

Third.  The  speech  and  comfort  of  the  wearer  are  often  af- 
fected by  these  self-cleansing  slots  under  the  front  teeth. 

Fourth.  The  teeth  employed  as  abutments  are  usually  irrep- 
arably destroyed  by  the  process  of  crowning. 

Fifth.  If  an  extensive  bridge  is  made  of  gold,  being  immova- 
ble, it  is  impossible  to  keep  it  perfectly  clean,  as  the  metal  Avill 
gradually  tarnish  in  parts  out  of  reach  of  the  brush,  and  will 
gather  ofi"ensive  matter  on  its  surface  and  in  its  interstices. 

Sixth.  In  cases  where  it  becomes  necessary  to  temporarily  re- 
move the  bridge  for  the  purpose  of  repair,  or  because  of  disease 
in  the  teeth  which  support  it,  the  operation  is  difficult  and  the 
bridge  is  usually  injured  so  as  to  unfit  it  for  reinsertion. 

Seventh.  The  teeth  which  support  the  bridge  are  required  to 
bear  more  force  and  pressure  than  nature  intended,- — where  the 
piece  is  large  many  times  more, — and,  the  bridge  being  perma- 
nently attached,  at  no  time  can  any  rest  be  given  the  abutments  or 
the  contiguous  parts  by  its  temporary  removal.  Thus  in  a  piece 
of  bridge-work  of  fourteen  teeth  supported  by  caps  or  crowns 
on  four  natural  ones,  each  one  of  the  natural  teeth  may  have  to 
bear  more  than  three  times  the  strain  in  supporting  the  weight 
of  the  denture  and  the  force  of  mastication,  that  was  intended. 
The  ultimate  result  is  evident  to  any  one  who  is  experienced  in 
dental  practice;  and  unless  the  anatomical  conditions  are  most 
favorable,  the  usefulness  and  durability  of  such  work  is  decidedly 
limited  in  character,  considering  the  time,  trouble,  and  great  ex- 
pense attending  it. 

Such  are  the  objections  which  have  been  put  forth  against 
bridge- work;  and  yet,  whatever  may  be  urged  against  it,  its  ad- 
vantages have  won  from  a  majority  of  the  profession,  including 


BRIDGE-WORK.  149 

many  accepted  authorities,  an  enthusiastic,  almost  a  sensational, 
indorsement;  some  practitioners  even  going  so  far  as  to  proclaim 
it  the  only  true  method  for  the  insertion  of  artificial  teeth. 

Judged  impartially,  bridge-work  has  many  advantages  when 
practiced  by  experts  who  properly  construct  and  apply  it.  With- 
out doubt  it  has  been,  and  is  still,  abused.  Bridges  have  been 
inserted  where  the  support  was  insufficient,  or  the  construction 
was  wrong  in  principle  or  faulty  from  lack  of  skill.  More  than 
this:  bridge-work  has  been  passing  through  the  experimental 
period,  when  failures  are  apt  to  appear  more  prominently  than 
successes.  The  chronicles  of  dental  literature,  however,  in  this 
respect  offer  only  a  repetition  of  the  historical  difficulties  that  at- 
tend all  new  departures  in  the  arts. 


CHAPTEE    I. 

CONSTRTJCTION  OF  BEIDGE-WORK. 

To  the  skilled  mechanical  dentist,  well  versed  in  metal-  and 
crown-work,  bridge-work  does  not  present  extreme  difficulty. 
The  foundations  or  abutments — that  is,  the  teeth  or  roots  on  which 
the  bridge  will  rest — are  first  to  be  considered,  due  respect  being 
paid  to  the  mechanical  principles  controlling  the  leverage  and  the 
force  of  occlusion  in  mastication.  The  amount  of  strain  that  can 
be  borne  by  the  different  teeth,  individually  and  collectively,  ac- 
cording to  their  position  and  condition  of  health,  should  be  care- 
fully calculated.  As  a  rule,  the  force  exerted  upon  the  incisors  in 
occlusion  will  be  directed  outward  on  the  upper,  and  inward  on 
the  lower  teeth,  and  its  tendency  when  they  support  a  bridge  will 
be  to  gradually  push  them  out  of  line  in  each  direction.  When 
the  incisors  are  replaced  by  a  bridge,  the  tendency  of  the  force  of 
occlusion  is  toward  a  similar  result.  On  the  bicuspids  and  molars 
the  force  is  direct.  The  rules  which  govern  the  number  and  posi- 
tion of  the  teeth  or  roots  required  as  foundations  for  bridges  in 
practice,  are  as  follows: 

One  central  root  will  support  two  centrals,  and  if  spurs  or  bars 
from  the  sides  of  the  bridge  rest  upon  or  are  anchored  in  the  ad- 
joining teeth,  a  lateral  in  addition. 

Two  central  roots  will  support  the  four  incisors,  spurs  or  bars 
resting  on  or  anchored  in  the  cuspids  to  be  used  additionally,  if 
the  case  requires  them. 

The  cuspid  roots,  alone,  or  with  the  aid  of  a  central  root,  will 
support  the  six  anterior  teeth. 

Oiie  molar  or  bicuspid  on  one  side,  and  a  bicuspid  or  molar 
on  the  other,  with  one  or  two  roots  in  an  intermediate  position, 
will  support  a  bridge  between  them. 

One  right  and  one  left  molar,  with  the  assistance  of  the  two 
cuspids,  Avill  support  a  bridge  comprising  the  arch  between  them. 

A  bridge  on  one  side  of  the  mouth  can  be  supported  by  two 
or  three  teeth  or  roots  on  that  side.     The  cuspids  always  afford 
the  most  reliable  support. 
150 


CONSTRUCTION  OF  BRIDGE-WORK. 


151 


In  general,  the  application  of  these  principles  will  cover  the 
subject  of  foundations,  the  operator  being  governed  by  the  exact 
condition  of  individual  cases.  In  a  bridge  of  the  six  anterior 
teeth  on  the  two  cuspids,  when  the  articulation  of  the  antagonizing 
teeth  is  close  and  deep,  the  strain  should  be  relieved  by  an  addi- 
tional attachment  of  the  bridge  to  the  teeth  posterior  to  the  cus- 
pids. 

Fro.  270. 


The  preparation  of  teeth  or  roots  to  support  a  bridge  is  the 
same  as  for  ordinary  crowns,  except  that  the  trimming  of  the 
sides  and  the  drilling  of  the  root-canals  of  the  various  anchorages 
should  be,  as  far  as  possible,  in  parallel  lines,  so  that  the  collars 
and  posts  of  the  crowns  shall  move  readily  to  their  places  in  the 
adjustment  of  the  finished  bridge.,  Teeth  or  roots  which  are  to 
be  supplied  with  porcelain-faced  or  all-gold  cap-crowns  are  crowned 
by  some  one  of  the  methods  already  described.  The  roots  which 
are  to  carry  porcelain-faced  crowns  can  be  so  crowned  or  only 
capped,  the  posts  being  soldered  and  allowed  to  project  a  short 
distance  beyond  the  caps. 

The  case  represented  in  Mg.  270  will  be  used  to  illustrate  the 
construction  of  a  piece  of  bridge-work  in  all  its  details.  The  abut- 
ments, or  supports,  consist  of  the  right  second  molar  capped  with 
an  all-gold  crown,  constructed  in  sections  by  first  forming  the  col- 
lar and  then  soldering  on  the  cap  (see  page  87),  the  two  cuspid 
roots  capped  for  collar  crowns  with  porcelain  fronts  (see  page  79), 


152 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


and  the  left  first  molar,  which  will  afford  anchorage  to  a  bar  on  that 
side  of  the  bridge  (Fig.  271).  A  slot,  dovetail  in  form,  is  usually 
cut  well  into  the  body,  but  not  to  an  extent  that  will  endanger  the 
pulp  of  the  last-named  crown  (Fig.  272).  If  the  tooth  is  not  de- 
cayed, it  can  be  first  opened  up  with  a  rubber  and  corundum  disk. 
The  shaping  of  the  slot  is  best  accomplished  with  fissure-burs. 
With  the  crowns  and  caps  in  position,  an  impression  and  articula- 
tion of  the  case  are  then  taken  with  plaster^  slightly  colored  with 
carmine,  to  which  is  added  a  little  sulfate  of  potassium,  less  than 
the  proportion  of  salt  generally  used,  which  causes  it  to  set  quickly. 


Fig.  271. 


Fig.  272. 


The  plaster  is  mixed  moderately  thick,  and  with  the  aid  of  a 
spoon  or  rolled  in  a  mass  in  the  fingers,  which  should  be  wet  to 
prevent  adhesion  of  the  plaster,  is  placed  around  in  the  mouth  on 
the  crowns,  caps,  and  parts  to  be  included  in  the  bridge,  and  the 
antagonizing  teeth  occluded  tightly  and  so  held  until  the  plaster 
sets.  The  mouth  -is  then  opened  and  the  plaster  carefully  re- 
moved, the  pieces  being  adjusted  together  should  it  break.  The 
crowns  and  caps  (the  latter  held  more  firmly  by  the  protruding 
ends  of  the  pins)  are  generally  removed  in  the  impression;  if 
not,  they  should  be  transferred  from  the  mouth  to  it.  The  plaster 
is  then  varnished  and  oiled,  and  on  the  side  containing  the  crowns 

^Impression  compound  is  used  to  some  extent  for  this  purpose  instead  of  plas- 
ter, but  in  the  author's  opinion  cannot  be  recommended  as  suitable. 


CONSTRUCTION  (>F  HRIDHE-WORK. 


153 


a  model  is  run,  composed  of  equal  parts  of  calcined  marble-dust 
and  plaster,  to  which  a  little  sulfate  of  potassium  is  added.  AVhen 
the  model  has  set,  it  is  mounted  with  plaster  on  an  articulator,  and 
the  other  side  of  the  colored  plaster  impression  giving  the  articu- 
lation is  run  with  plaster  and  the  opposite  section  of  the  articulator 
adjusted.  AVhen  the  impression  plaster  is  removed  fan  operation 
which  is  greatly  facilitated  by  its  having  been  colored  with  car- 
mine), a  correct  model  and  articulation  of  the  case  will  be  found, 
with  the  crowns  and  caps  in  exact  position  as  in  the  mouth  (Fig. 
278). 

Fig.  273. 


Another  method  is  to  fii'st  take  the  articulation  in  wax  vrith  the 
caps  and  crowns  in  position  in  the  mouth,  and  then  the  impression 
in  an  impression-tray  ^\ix\l  plaster,  and.  make  a  model  and  articula- 
tion from  them  in  the  usual  manner. 

Dr.  Melotte's  method  is  to  place  a  piece  of  impression  com- 
pound in  the  space  between  the  crowns  to  be  occupied  by  a  bridge, 
and  occlude  the  teeth.  The  compound  is  then  chilled,  removed, 
trimmed,  and  readjusted  until  it  accurately  fits  the  space,  when 
it  is  placed  in  position  and  an  impression  is  taken  with  plaster. 
TThen  the  impression  is  removed,  iron  pins  to  act  as  dowels  are 
placed  in  the  portions  representing  the  natural  teeth,  and  then 
several  pieces  of  fusible  metal,  by  a  few  puffs  of  flame  from  the 
blow-pipe,  are  melted  in  around  the  pins.  The  rest  of  the  impres- 
sion is  then  run  with  plaster  and  marljle-dust  in  the  usual  manner. 
This  forms  a  plaster  model  on  which  the  natural  teeth  are  rep- 


154 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


resented  in  metal.  These  metal  teeth  are  to  be  removed  before- 
investing  in  soldering  the  bridge.  An  impression  of  the  occlud- 
ing teeth  is  taken  in  plaster,  and  the  entire  impression  run  with 
fusible  metal.  When  the  plaster  impression  is  removed  from  the 
model  of  the  bridge,  the  piece  of  impression  compound  betv^een  the- 
crowns  is  to  be  left  in  position,  and  the  metallic  model  of  the 
Occluding  teeth  fitted  in  position,  guided  by  the  indentations  of  the 
occluding  teeth  in  the  compound,  and  the  case  mounted  on  an  ar- 
ticulator. The  principal  object  of  this  method  is  to  avoid  fracture - 
of  forms  of  natural  teeth,  both  in  removal  from  impressions  and  ini 
the  construction  of  the  bridge-work. 

The  pins  protruding  from  the  caps  on  the  model  are  next  cut 
off  short.  Teeth  are  selected, — ordinary  cross-pin  plate  teeth  for 
the  incisors  and  cuspids,  and  partial  teeth,  representing  the  front 
section  of  the  tooth  and  styled  porcelain  facings,  which  were 
specially  designed  for  crown-  and  bridge-work,  for  the  bicuspids 
and  molars  (Fig.  274).     Cuspids  are  sometimes  used  to  form  the 

fronts  for  bicuspids.     The  teeth 
^^^-  ^'^^-  are    ground    and   fitted    to    the 

model  and  articulation,  so  that 
the  labial  upper  edge  of  the- 
teeth  shall  press  lightly  on  the- 
gum.  Those  which  are  in- 
tended to  form  the  fronts  of 
the  caps  on  the  cuspid  roots 
should  be  adjusted  in  the  ordi- 
nary manner  for  single  crowns.. 
To  determine  the  proper  posi- 
tions of  the  teeth  for  producing 
the  best  appearance,  they  can  be- 
adjusted  in  the  mouth  on  wax, 
without  the  gold  crowns  or  caps  of  the  supports.  The  correct 
position  of  the  teeth  on  the  model  having  been  obtained,  investing 
material,  composed  of  one  part  plaster  to  two  of  calcined  marble- 
dust,  is  placed  on  the  outside  of  the  model  on  the  labial  aspect 
of  the  teeth,  merely  sufficient  in  quantity  to  hold  them  in  position, 
thus  forming  a  matrix,  or,  the  matrix  can  be  formed  of  plaster  and 
entirely  removed  before  investing  for  soldering.  The  wax  is  then 
removed,  exposing  the  palatal  portion,  and  permitting  the  forms 


CONSTRUCTION  OF  BRIDGE-WORK. 


156 


and  position  of  the  teeth  to  be  studied  (Fig.  275).  The  porcelain 
teeth  or  fronts,  with  the  exception  of  fronts  for  the  roots  capped^ 
are  then  removed  from  their  investment,  and  the  base  ground  from 
a  line  on  the  palatal  side  below  the  pins,  straight  to  the  labio-cervi- 
cal  edge  (A  and  B,  Fig.  275).  This  is  to  form  the  self-cleansing 
spaces.  The  incisors  are  then  backed,  using  either  thin  platinum 
or  pure  gold  (C).  The  backings  are  allowed  to  extend  just  over 
the  incisive  edge  as  a  protection  to  it,  and,  if  preferred,  down  on 
the  curve  of  the  self-cleansing  space.     A  more  desirable  result  i& 


Shows  "dummies"  in  various  stages  of  construction.  A,  central  incisor,  and  B,  bicuspid,, 
ready  for  metallic  backing.  C  is  a  central  backed.  D,  D,  D,  porcelain  fronts  as  they  appear  on 
insertion  after  the  process  of  backing,  capping,  and  soldering. 


secured  if  the  backing  extends  only  to  the  edge  of  the  self -cleans^ 
ing  space,  and  the  porcelain  is  polished,  as  its  surface  is  superior  in 
cleanliness  to  that  of  gold.  If  the  platinum  backing  used  is  sO' 
exceedingly  thin  as  to  be  of  the  nature  of  foil,  it  is  advisable  to 
rivet  a  small  piece  of  gold  plate  over  it  on  the  back  of  the  tooth, 
to  insure  against  melting  the  platinum  off  the  porcelain  with  the- 
gold,  which  is  apt  to  occur  if  a  pointed  flame  is  directed  against  it. 
The  cuspids  are  backed  in  the  manner  described  for  collar  crowns. 


156 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  bicuspid  and  molar  porcelain  fronts,  their  tips  being  ground 
off  (A,  Fig.  276),  are  lined  in  a  similar  manner.  A  cap  of  pure 
gold  or  gold  lined  with  platinum,  representing  the  grinding-surf  ace 
of  each  tooth,  is  struck  up  as  described  and  illustrated  in  the  con- 
struction of  gold  crowns  (see  page  88),  and  the  Concave  portion 
filled  bj  melting  in  scraps  of  20-carat  gold  plate  or  solder.  The 
surface  is  then  ground  smooth  (B),  and  closelj  fitted  to  the  tip  of 
the  porcelain  front  to  form  the  occluding  surface  in  accordance 


Fig.  276. 


Fig.  277. 


with  the  articulation  of  the  lower  teeth,  and  the  space  filled  in  with 
wax.  This  metallic  occluding  surface  is  to  protect  the  porcelain. 
Triangular  pieces  of  very  thin  gold  plate,  platinum,  or  IsTo.  60 
gold  foil,  or  mica  (C),  cut  and  fitted  to  the  sides,  over  which  they 
should  extend  slightly,  will  retain  the  gold  in  position  when 
melted,  but  are  seldom  necessary.  The  tooth  is  next  invested, 
leaving  the  back  open,  presenting  the  form  of  a  pocket  (Fig.  'ill)} 
Fig.  278.  Another    method    of    constructing   bicuspid    and 

molar  dummies  is  to  fit  the  cap  to  the  labial  edge 
of  the  porcelain  front,  back  the  porcelain  with  thin 
platinum,  extending  the  backing  over  and  between 
the  porcelain  and  cap,  and  then  filling  in  the  space 
with  gold  in  soldering,  as  shown  at  A,  in  Fig.  278. 
The  bar  intended  to  be  anchored  in  the  slot  cut 
in  the  molar  on  the  left  side  is  made  of  iridio-platinum  wire,  about 
~So.  15  U.  S.  standard  gauge,  with  the  end  shaped  as  shown  in 
Fig.  279,  and  fastened  with  wax  to  the  tooth  and  cap,  ^^^  279. 
and  adjusted  in  the  mouth  to  obtain  accuracy  of  posi- 
tion before  soldering. 

The  advisability  of  constructing  bridge-work  with 
what  are  termed  self -cleansing  spaces  is  not  favorably 

^See  the  Hollingsworth  System  for  description  of  method  of  swaging  grinding- 
surfaces  of  several  crowns  and  dummies  on  one  piece  of  plate. 


CONSTRUCTION  OF  BRIDGE-WORK.  157 

accepted  of  late  by  many  practitioners.  Instead,  the  following 
method  is  adopted:  Porcelain  fronts  thicker  in  the  line  from  the 
labial  to  palatal  side  than  those  most  commonh^  nsed  are  selected. 
The  base  or  cervical  section  of  the  porcelain  is  ground  and  fitted  to 
the  alveolar  ridge  very  accurately.  The  fronts  are  then  waxed  in 
position,  and  with  a  fine-pointed  lead-pencil  a  line  is  drawn  ac- 
curately around  the  base  of  each  porcelain  front  on  the  model. 
The  fronts  are  then  removed,  and  with  a  suitable  scraper  the 
plaster  under,  and  only  under,  the  base  of  each  is  removed  uni- 
formly the  thickness  of  cardboard.  The  porcelains  are  then  fitted 
back  in  position  with  the  bases  in  the  indentations.  The  work  is 
then  proceeded  with  in  the  usual  manner.  When  the  bridge  is 
finished  and  inserted,  the  base  of  each  porcelain  will  uniformly 
indent  the  gum  to  the  depth  the  plaster  was  removed,  and  the  con- 
formation will  also  exclude  particles  of  food  and  present  a  much 

Fig.  280.  Fig.  281. 


more  agreeable  shape  to  the  tongue  and  a  better  appearance  for 
the  patient.  The  shape  a  bicuspid  dummy  would  assume,  con- 
structed as  described,  is  shown  in  Fig.  278.^ 

The  teeth  forming  the  bridge  between  the  crowns  are  called 
"dummies."  In  the  construction,  of  dummies  it  is  well  to  favor 
the  occluding  surface  by  shaping  it  a  trifle  narroiver  from  labial 
to  palatal  side  than  the  corresponding  natural  tooth  was. 

All  the  porcelain  teeth  or  fronts  can  be  invested  at  the  same 
time,  including  the  incisors  and  porcelain  fronts  to  the  cuspid 
crowns,  as  shown  in  Fig.  280.  In  the  soldering,  if  the  backing 
is  done  vnth  platinum,  and  the  occluding  surface  of  the  bicuspids 
and  molars  made  with  24-carat  gold  or  gold  lined  with  platinum, 
18  or  20-carat  gold  plate  or  hard-flowing  solder  (see  page  79)  may 

^  The  author,  at  present,  in  his  own  practice  constructs  most  of  his  worlc  in  this 
manner. 


158 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


be  melted  into  the  pockets  formed  by  the  cap  and  side  pieces  to 
fill  out  to  the  line  at  A,  Fig.  281,  and  flowed  over  the  backings 
of  the  incisors  and  cuspid  fronts  in  sufficient  quantity  to  shape 
them  as  shown  at  B,  Fig.  282.  When  the  backing  and  occluding 
surfaces  are  made  of  18  or  20-carat  gold  plate,  18  or  20-carat 
solder  and  small  pieces  or  filings  of  gold  plate  should  be  used 
instead.  After  the  soldering  and  removal  of  the  borax  with 
acid,  the  metal  of  each  tooth  is  then,  when  it  is  easily  done,  very 
carefully  trimmed  and  shaped  with  corundum-wheels  and  points. 


Fig.  282. 


Fig.  283. 


The  teeth  are  next  placed  in  their  relative  positions  on  the 
model  as  shown  at  D,  D,  D,  Fig.  275,  and  attached  to  one  another 
with  wax  in  exactly  the  relation  and  only  where  they  are  to  be 
united  with  the  gold  solder.  The  model  is  then  detached  from 
the  articulator,  trimmed  down  as  much  as  possible  in  size,  and 
additional  investing  material,  composed  of  two  parts  marble-dust 
and  one  of  plaster,  or  one  part  plaster,  one  marble-dust,  and  one 
common  white  sand,  applied  until  all  of  the  bridge  is  covered  ex- 
cept the  space  along  the  backings  and  crowns  where  they  are  to  be 
united  in  the  soldering.  To  prevent  fracture  during  the  process 
of  soldering,  which  might  readily  occur  from  contraction  in  so 
large  an  investment,  an  iron  wire  or  a  narrow  horse-shoe  shaped 
strip  of  sheet  iron  should  be  placed  in  the  investment  so  as  to  en- 
circle the  teeth  and  crowns  about  one-fourth  of  an  inch  from  their 
exterior  surface  (Fig.  283).     In  any  spacings  between  the  back- 


CONSTRUCTION  OF  BRIDGE- WORK.  159 

ings  pieces  of  gold  or  platinum  plate  or  wire,  about  one-eighth  of 
an  inch  long,  are  placed  lengthwise,  and  the  joints  well  soldered. 
When  the  backings  have  been  soldered  with  gold  plate  or  hard- 
flowing  solder,  20-carat  solder  may  be  used.  If  the  backings  were 
.done  with  20-carat  solder,  an  easy-flowing  18-carat  solder  should 
ibe  used.  The  soldering  is  best  done  with  a  gas  blow-pipe  on  a 
ipiece  of  charcoal  with  a  concave  depression  (see  chapter  on  Solder- 
ing). When  the  bridge  is  removed  for  finishing,  the  joints  of  the 
backings  and  crowns  are  finished  with  corundum-wheels  and  points 
.and  leather  polishing-wheels  on  the  engine,  and  the  entire  bridge 
finely  polished  with  whiting  carried  by  a  brush-wheel  on  the  lathe. 
Any  little  pits  that  may  exist  can  be  filled  in  with  gold  foil.  The 
bridge  is  then  ready  for  insertion  (Fig.  284).  If  the  constructive 
details  have  been  properly  per-  Fig.  284. 

formed  as  described,  a  finished 
piece  of  bridge-work  is  the  re- 
•sult. 

In  constructing  bridge-work 
many  prefer,  after  the  porcelain 
fronts  are  backed  and  the  caps 
forming  the  occluding  surfaces 
•of  the  bicuspids  and  molars  are 
properly  adjusted  on  the  model, 
to  invest  and  do  the  entire  sol- 
dering at  once.  When  this  plan 
is  followed,  pieces  of  gold  wire  or  plate  should  be  laid  lengthwise 
in  the  slots  under  the  gold  caps  of  the  porcelain  fronts,  and  the 
parts  filled  in  and  all  the  sections  of  the  bridge  joined  together  in 
the  soldering.  By  this  method  there  is  less  liability  of  fracturing 
the  porcelain  fronts,  but  warping  is  more  apt  to  occur,  and  the 
-finishing  of  the  bridge  is  not  so  easily  done. 

In  large  pieces  of  work  warping  may  be  avoided,  whichever 
method  of  soldering  is  adopted,  by  first  removing,  in  proper  posi- 
tion, the  "dummies,"  and  soldering  those  of  each  span  together. 
The  spans  are  then  replaced  in  the  matrix  and  soldered  to  the 
abutments. 

Another  method  much  practiced  is  to  construct  the  bridge  in 
sections,  adjust  the  sections  in  the  mouth,  and  remove  them  in  an 
impression-tray,  using  only  sufficient  investing  material  to  cover 


160 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


the  points  of  the  teeth  and  crown^  as  shown  in  Fig.  285.  The 
bridge  and  the  investing  material  are  then  removed  from  the  im- 
pression-tray, and  more  investing  material  is  added  to  complete 
the  investment.  The  sections  of  the  bridge  to  be  united  are  then 
exposed  and  soldered  together.  To  enable  the  investing  material 
to  be  easily  removed  from  the  impression-tray,  it  is  well  to  melt 
a  film  of  wax  on  the  interior  surface,  then  cool  and  serrate  the 
surface  of  the  wax.  The  plaster  will  firmly  adhere  to  the  wax, 
but  will  loosen  when  the  tray  is  heated.  In  the  case  just  described, 
the  right  and  left  cuspids  and  molar  sections  could  be  made  first,, 
adjusted  in  position,  the  incisors  then  formed  between  them,  and 
all  soldered  together;  or,  the  front  section,  consisting  of  the  cus- 
pids and  incisors,  could  be  first  made,  and  then  the  rear  exten- 
sions to  the  molars  added. 

Fig.  286. 


Adjustment  and  Attachment. — The  bridge  when  finished  is  ad- 
justed in  the  mouth,  every  point  carefully  examined,  and  any 
alterations  required  are  then  made.  Should  the  edges  of  the 
collars  of  any  of  the  crowns  catch,  so  as  to  prevent  their  being 
-placed  in  position,  a  small  quantity  of  articulating  paste  (a  thin 
paste  of  rouge  and  oil)  should  be  applied  inside  the  cap  or  caps 
interfering,  and  the  point  found  and  trimmed  off.  If  extensive- 
warping  has  occurred  in  the  soldering,  the  bridge  must  be  sawed 
apart  in  one  or  two  places,  adjusted  in  the  mouth,  and  removed 
in  an  impression-tray.  Only  sufficient  investing  material  to  cover 
the  points  of  the  teeth  and  crowns  (Fig.  285)  should  be  used  as 


Fig.  286. 


CC)NSTRUCTI()N  OF  JililDd K-WORK.  Igl 

just  described  in  construction  of  a  bridge  in  sections,  more  invest- 
ment material  being  added  after  removal,  and  the  sections  sol- 
dered together. 

When  the  adjustment  of  the  bridge  is  accomplished,  it  can  at 
first  be  temporarily  inserted  for  a  day  or  two,  if  desired,  which 
permits  it  to  settle  accurately  in  position.  If  the  bridge  is  warmed 
and  paraffin  to  which  a  little  aristol  has  been  added  is  placed  in  the 
caps  before  inserting,  the  secretions  vdll  be  better  excluded  and 
a  septic  odor  prevented.  Burnishing  the  collars  will  usually  se- 
cure the  bridge;  if  not,  it  can  be  cemented  with  a  little  gutta- 
percha placed  in  each  cap,  instead  of  the  paraffin.  For  its  per- 
manent attachment  the 
pins  or  posts  of  the  crowns 
are  barbed,  and  the  teeth 
and  roots  to  which  crowns 
have  been  fitted  are  then 
treated  the  same  as  single 
crowns,  and  the  bridge  ce- 
mented on  with  oxyphos- 
phate  cement  or  gutta- 
percha. The  end  of  the 
bar  is  anchored  in  the  slot 
by  either  a  gold  or  an  amal- 
gam filling  (see  chapter  on  Bar  Bridges).  Fig.  286  represents  the 
bridge  in  position. 

The  Construction  of  Small  Pieces  of  Bridge-work  is  much  sim- 
plified by  the  following  method:  Crowns  are  first  made  for  the 
teeth  or  roots  that  form  the  abutments  and  temporarily  placed  in 
position.  The  teeth — "dummies" — which  form  the  span,  having 
been  ground  and  backed,  are  adjusted  and  cemented  with  resin 
and  wax  in  proper  position  between  the  crowns.  The  crowns  and 
dummies  are  then  removed  together,  in  an  impression-tray  filled 
with  investing  material.  The  inside  of  the  tray  should  be  previ- 
ously oiled  or  coated  with  a  film  of  wax  with  a  serrated  surface. 
The  impression-tray  is  then  heated,  and  the  investment  with  the 
crowns  and  dummies  removed;  more  investing  material  is  then 
mixed,  and  the  exposed  parts  of  the  crowns  and  teeth  covered. 
The  investment,  when  set,  is  then  cut  away  sufficiently  to  expose 
the  parts  that  are  to  be  filled  in  and  united  together  in  the  pro- 

12 


162 


ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 


cess  of  soldering.     Figs.  287,  288,  represent  cases  of  bridge-work 
constructed  in  this  manner. 


Fig.  287. 


Fig.  288. 


In  a  bridge  of  two  teetli,  often  a  preferable  method  is  to  prop- 
erly adjust  crown  and  dummy  tooth  cemented  with  wax  in  the 
raouth,  carefully  remove  them  in  position  from  the  mouth,  then 
invest  and  solder  together. 


Fig.  289. 


Fig.  290. 


CHAPTER    II. 

SPECIAL  PROCESSES  AND  APPLIANCES  IN  BRIDGE- WORK. 

8houldters  on  Anterior  Crowns  or  Artificial  Teeth  are  sometimes 
desirable,  especially  on  the  superior  cuspids  at  the  point  of  occlu- 
sion with  the  lower  teeth.  A  shoulder  can  be  made  by  melting 
gold  plate  into  the  form  of  a  small  ball  or  globule,  then  flattening 
it  out  and  soldering  it  against  the  backing. 

Another  method  is  to  attach  with 
wax  transversely  across  the  backing  in 
proper  position  a  strip  of  gold  plate  as 
shown  in  Fig.  289,  and  then  flow  in 
gold  to  the  line  A,  by  specially  invest- 
ing or  in  the  soldering  of  the  bridge. 
The  strip  of  gold  should  be  extended  a 
iittle  beyond  both  sides  of  the  backing  or  over  the  incisive  edge 
of  the  porcelain  to  retain  it  in  position  in  the  investment. 

Solid  Porcelain  Dummies  with  Gold  Base. — In  some  cases  of 
bridge- work  on  the  lower  jaw,  protection  of  the  incising  edges  and 
occluding  surfaces  of  dummies  with  gold  renders  them  noticeable 
to  an  extent  which  is  very  objectionable  to  vciawj  patients.  This 
can  be  remedied  in  bicuspids  by  forming  the  occluding  surface 
and  the  exposed  portion  of  the  labial  face  of  the  porcelain  in  the 
following  manner:  Select  a  suitable  sized  ordinary  bicuspid  de- 
signed for  vulcanite,  and  level  out  the  headed  portion  of  the  pins 
by  squeezing  with  pliers.  Cut  a  strip  of  pure  gold  about  JSTo.  34 
gauge,  of  a  size  to  encircle  the  tooth  and  give  an  excess  in  length 
and  width  of  about  one-eighth  of  an  inch.  Trim  the  strip  to 
the  shape  seen  at  Fig.  291,  and  punch  a  hole.  A,  in  one  of  the 
corners.  Slij)  this  over  the  left-hand  pin  A,  Fig.  292,  wrap  the 
gold  tightly  around  the  porcelain,  and  bring  it  over,  as  shown 
by  the  dotted  line,  on  to  the  right-hand  pin  marked  B.  Mark 
the  location  of  the  pin  and  punch  a  hole,  put  the  pin  through 

163 


164 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


tlie  hole  and  bring  tlie  gold  down  on  tlie  porcelain.     Outline 
on  the  gold  enough  to  expose  the  porcelain  as  shown  in  Fig. 


Fig.  291. 


Fig.  292. 


293.  Eemove  the  gold  and  cut  out  the  portion  marked.  Replace 
the  gold  on  the  tooth,  pinch  in  around  the  base  of  the  porcelain, 
Fig  293  ^^^  ^^^  ^^  ^^  excess  of  length,  also  the  excess  at  the 
overlap  on  a  diagonal  line  so  as  to  make  an  even  joint. 
Bend  the  pins,  invest  and  flow  solder  over  pins  and 
seam.  When  completed  you  will  have  a  dummy  of 
the  form  exhibited  in  Fig.  293,  which  can  be  placed 
in  position  and  attached  with  solder. 

Bolid  Gold  Crowns. — In  a  close  articulation,  when  the  patient 
prefers  strength  to  appearance,  the  bicuspids  and  molars  may  be 
made  of  solid  gold.  They  are  constructed  by  stamping  up  the 
cap  (A,  Fig.  290)  representing  the  grin  ding-surface  (see  page  86), 
adjusting  and  cementing  to  this  with  wax  a  piece  of  plate  cut  and 
shaped  to  form  the  front  and  sides  (B),  the  whole  being  then  in- 
vested and  filled  in  with  gold  solder,  or,  if  pure  gold  and  platinum 
has  been  used  in  the  sections  of  the  crown,  with  18-  or  20-carat 
plate. 

Seamless  contour  crowns  can  be  used  for  the  purpose  as  follows : 
The  proper  crowns  having  been  selected,  the  gold  is  trimmed  and 
the  crowns  adjusted  in  position  on  the  model.  A  matrix  of  plaster 
is  then  placed  on  the  labial  side,  which  permits  exposure  of  the 
palatal  portion,  the  crown  removed,  and  cut  away  to  the  form  re- 
quired. They  are  then  removed,  invested,  and  filled  in  with  scraps 
of  gold  plate  and  solder. 

A  bar  bridge  can  be  made  with  these  seamless  crowns  by  passing 
an  iridio-platinum  wire  through  the  crowns  before  filling  in  (Fig. 
294). 

A  Solid  Gold  Croivn  for  a  Pulpless  Molar,  supporting  the  end 
of  a  bar  as  shown  in  Fig.  295,  is  constructed  as  follows:  The 
natural  crown  is  ground  down,  banded,  capped,  and  pivoted  as 


SPECIAL  PROCKSSKS  AND  APPLIANCES  IN  BRIDd E-\V(Jllh'.     165 


in  Fig.  296.     The  gold  or  platinum  forming  the  top  of  the  cap  on 
the  root  is  made  perfectly  flat  and  left  projecting  a  little  at  the 


Fig.  294. 


Fig.  295. 


Fig.  296. 


sides.     A  contoured  crown  of  pure  gold,  or  gold 

lined  with  platinum  as  a  precaution  against  melting, 

is  shortened  sufiiciently  to   represent  the   absent 

coronal  section  of  the  tooth.     In  the  side  of  the 

gold  crown  a  slot  is  cut  large  enough  to  form  the  anchorage  cavity 

the  bur  is  to  rest  in.     A  shell  of  thin  platinum  of  the  size  and 

shape  of  the  anchorage  cavity  is  then  inserted  in  the  slot  and 

cemented  with  wax  on  the  inside  of  the  crown.     The  crown  is 

Fig.  297. 


then  invested  and  filled  with  18-carat  gold  solder,  which  should 
be  cut  into  small  pieces,  and  be  placed  successively  in  the  crown 
and  melted  by  maintaining  a  uniform  heat  with  the  large  flame 
of  a  blow-pipe.  The  base  of  the  crown  is  next  ground  level  and 
accurately  fitted  to  the  cap  and  articulated  to  the  antagonizing 
teeth.  It  is  then  clamped  in  position  to  the  cap,  the  pivots  of 
which  are  protected  with  investing  material  (Fig.  297),  and  sol- 
dered, making  a  perfect  joint.  This  is  an  easy  method  of  con- 
structing an  otherwise  diflicult  form  of  crown. 

Fig.  298  illustrates  from  the  palatal  side  a  bridge  of  two  solid 
gold  bicuspid  dummies  supported  by  a  bar-anchorage  in  a  solid 
gold  crown  on  the  roots  of  a  molar,  and  a  shell  crown  on  a  cuspid. 


166 


ARTIFICIAL  CROWX-  AXD  BRIDGE-WORK. 


All-gold  Hollow  Dummies  are  recommended  in  a  large  propor- 
tion of  eases  in  preference  to  solid  ones.  Tliej  are  formed  as 
follows:  Take  a  gold  seamless  contour  crown  of  suitable  size,  with 
a  thick  g-iindiug-siirface,  or  one  which  has  been  reinforced  with 
solder  or  gold  plate  and  with  the  flux  removed,  and  cnt  away  the 
gold  forming  the  palatal  section  of  the  collar  to  the  form  termed 
self-cleansing;  or  shape  the  neck  of  the  crown  to  the  exact  contour 

Fig.  298. 


of  the  portion  of  the  giun  the  dummy  is  to  rest  on,  and  scrape  a 
little  from  the  surface  of  the  model  to  cause  pressm-e  and  insure 
closeness  of  fit.  Melt  a  small  quantity  of  solder  with  flux  to  a 
baU  form.  Fit  a  piece  of  platintmi  plate,  about  Xo.  32  gauge, 
oyer  the  aperture,  and  place  the  ball  of  solder  on  the  platinmn 
within  the  gold  cap  (see  Fig.  299).  Hold  cap  and  platinum  in  a 
Bunsen  flame,  and  heat  slowly  until  the  solder  melts  and  appears 


Fig 


Fig.  300. 


under  the  edge  of  the  cap;  then  instantly  remove  from  the  frame, 
trim  the  platinimi,  and  stone  the  edges.  '  This  gives  a  hermetically 
inclosed  dummy  tooth  of  gold,  from  the  inten'or  of  which  the  air 
has  been  exhausted  by  the  heat.  The  dummy  can  then  l^e  placed 
in  its  position  on  the  bridge  and  soldered  in  the  usual  manner. 
Fig.  300  gives  the  palatal  aspect  of  a  bridge,  the  dummies  of 
which  were  constructed  in  the  manner  described.  The  bicuspid 
dtmmiy  is  given  a  seK-cleansing  form,  and  the  molar  is  shaped  to 
rest  on  the  gum. 

The  use  of  hollow  gold  dummies  is  a  saving  of  time  and  ex- 


SPECIAL  PROCESSES  AND  Al'I'LIANCES  IS  P.ItUX l i:-\V< HlK.     \{^^^ 


Fig.  301. 


peiise  to  the  operator;  being  of  liglit  weiglit,  in  many  cases  they 
are  preferable  to  solid  ones.  For  the  lower  jaw  they  can  be 
shaped  advantageously  to  the  form  shown  in  Fig.  301, 
thus  overcoming  the  annoyance  of  the  so-termed  self- 
cleansing  spaces.  The  collar  section  of  the  crown  is 
slit  on  the  sides  A,  shaped  and  bent  inward  toward  the 
neck  at  the  buccal  as  well  as  lingual  sides,  and  the 
neck  trimmed  at  the  edges  to  fit  the  shape  of  the 
alveolar  ridge.  The  aperture  is  then  closed  with  jdati- 
num  as  shown  in  Fiff.  299. 


Fig.  302. 


Fig.  303. 


Fig.  304. 


Connecting  Bands  or  Bars  for  Bridges,  which  obviate  the  re- 
moval of  crowns  of  intervening  natural  teeth  between  the  sections 
of  a  projected  bridge,  are  formed  by  passing  a  heavy  band  of  oval- 


168 


ARTIFICIAL  GROWN- AND  BRIDGE-WORK. 


shaped  gold  or  iridio-platinum  wire  around  the  intervening  teeth, 
close  to  but  not  touching  them,  and  pressing  slightly  into  the 


Fig.  305. 


Tig.  306. 


gum  SO  as  not  to  present  too  pronounced  an  interference  to  the 
tongue.     (See  Figs.  302,  303,  and  304.) 


SPECIAL   PROCKSSKS  AND  APPLIANCES  IN  BUI ixi P.-WOPK.     169 


Fig.  307. 


Fig 


Intervening  Boots  between  the  abutments  of  a  projected  bridge 
should  not  be  extracted,  but  whenever  practicable  thej  should 
be  treated,  filled,  and  trimmed  level  with  the  gum,  as  they  can 
usually  be  made  to  afford  some  support  for  the  bridge,  which  may 
rest  upon  them.  Figs.  305  and  306  represent  a  case  in  which  the 
root  of  the  cuspid  on  the  right  side  has  been  so  treated  and  utilized. 

Shell  Anchorage  or  Crown. — A  shell  crown  or  anchorage  for  a 
cuspid  to  support  bridge-work  is  preferably  used  instead  of  a 
gold  collar  crown  with  porcelain  front,  where  the  insertion  of 
such  a  form  of  crown  involves  the  excision  of  a  natural  crown 
with  a  living  pulp.  A  convenient  method  of  construction  is  the 
following:  Shape  the  natural  crown  parallel  on  the  sides.  Con- 
struct and  adapt  to  the  cervix,  and 
slightly  under  the  gum-margin  of 
the  natural  crown,  a  gold  collar  wide 
enough  to  extend  a  little  below  the 
incisive  edge.  Remove  a  portion  of 
the  gold  from  the  incisive  labial  sec- 
tion, and  slit  the  palatal  surface  on 
both  sides  of  its  center,  as  repre- 
sented in  Figs.  307  and  308.  The  part  at  A  is  bent  back,  and  the 
parts  at  B,  B  beveled,  bent  in  on  the  crown,  and  burnished  close  to 
its  surface.  The  piece  A  is  next  brought  down  in  position,  and 
adapted  to  the  crown  and  over  the  parts  B,  B. 

The  collar  has  now  assumed  the  form  of  a  gold  crown  having  an 
open  face  and  seams.  The  seams  are  next  united  by  placing,  melt- 
ing, and  flowing  solder  into  each  of  them,  a  little  at  a  time,  by  hold- 
ing the  crown  with  tweezers  in  a  Bunsen  gas-flame.  The  seams 
will  hold  and  retain  solder  sufiicient  to  join  and  flU  them  without 
its  flowing  over  the  adjacent  parts,  unless  there  is  an  excess  of  heat 
or  solder.  When  the  soldering  is  completed,  the  crown  is  adjusted, 
a  line  showing  the  exact  portion  of  the  labial  aspect  to  be  exposed 
marked  on  the  gold,  the  crown  removed,  its  edges  trimmed  to  the 
mark,  and  the  soldered  parts  smoothed  with  corundum-wheels  and 
points  on  the  engine. 

Another  method  for  the  construction  of  a  shell  crown  prefer- 
ably practiced  by  some  is:  Fit  a  gold  collar  around  the  natural 
crown,  and  remove  the  gold  at  the  labial  aspect  as  shown  at  a, 
Fig.  309.     In  the  vacancy  between  the  collar  and  tooth  at  the 


170 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


palatal  side,  fit  and  biirnisli  a  piece  of  pure  gold  or  thin  platinum, 
which  will  cover  the  exposed  surface  of  the  tooth  at  that  part, 
and  fill  in  the  space  between  the  collar  and  piece  of  plate  with 
wax  cement,  d,  Fig.  309,  shows  the  form  generally  of  the  piece 
of  plate  before  it  is  fitted  in  the  collar.  Remove  the  collar,  invest, 
and  flow  solder  into  the  space  between  the  piece  of  plate  and  collar, 

•      Fig.  309. 


and  remove  the  surplus 
crown;  h  and  c  show  the 
A  Seamless  Shell  An 
impression  of  a  natural 
moldine,  a  die  of  fusible 
die  in  lead  is  made. 
Crown.")     On  the  die  a 

Fig.  310. 


gold  of  the  collar  extending  above  the 
finished  shell  crown. 

cliorage  is  formed  as  follows:  From  an 
crown  taken  in  plaster,  gutta-percha,  or 
metal  is  formed,  and  from  it  a  counter- 
(See  chapter  on  "Gold  Seamless  Cap- 
crown  is  stamped  from  a  seamless  cap  of 

Fig.  311. 


gold  (Fig.  310).  This  crown  is  then  fitted  on  the  natural  tooth, 
the  labial  aspect  of  which  is  exposed  by  the  removal  of  the  sec- 
tion of  gold  covering  it  in  either  of  the  forms  shown  in  Fig.  311. 
A  shell  for  a  cuspid  can  be  made  from  a  gold  collar  as  well  as  a 
cap.  The  shell  formed  in  either  manner  is  then  filled  with  in- 
vesting material,  and  strengthened  by  flowing  20-carat  solder  over 
the  surface. 


SPKC/AL   riKX'KSSIlS  AM)  M'I'LIA  XdlS  I .\  /!/,'//>(.■  I!- n< >Uh'.     IJl 


¥ov  cuspids  this  process  has  decided  advantages  in  the  easy 
formation  of  a  perfect- fitting  crown  or  shell  for  l)ridge-work. 

Fig.  312  shows  the  forms  usually  given  shell  crowns  for  Li- 
cuspids.  When  the  gold  is  removed  at  the  labio-cervical  part,  the 
croM'n  should  ])c  additionally  secured  Ity  a  pin  introduced  and  sol- 
dered at  the  point  A. 


Fkj.  312. 


Fi.;.   313. 


Fig.  313  illustrates  a  bridge  in  which  the  lower  incisors  are 
supported  by  shell  crowns  on  the  cuspids. 

In  cases  where  this  form  of  crown  is  expected  to  sustain  a 
great  strain,  the  gold,  at  the  cervico-labial  section  should  be  re- 
inforced hij  the  addition  of  a  strip  soldered  across  it  and  extending 
around  on  the  sides. 

Fig.    814. 


Fig.  314  represents  the  restoration  of  the  inferior  bicuspids  and 
molar  on  the  right  side,  by  a  bridge  with  a  shell  crown  on  the 
cuspid  and  an  all-gold  crown  on  the  second  molar  as  abutments. 

To  secure  a  better  adhesion  of  the  cement  in  the  cementation  of 
such  caps,  the  surface  of  the  enamel  should  be  cleaned  with  pul- 
verized pumice  wet  with  aromatic  sulfuric  acid.  The  tooth  is  then 
washed  and  dried  perfectly.  The  cement  should  be  thoroughly 
mixed  to  the  consistence  of  a  thick  cream,  the  inside  of  the  band 
covered  Avith  it,  and  then  the  surface  of  the  tooth  and  the  bridge 
brought  to  position. 


CHxiPTEK    III. 

EXTENSION  BRIDGES. 

This  term  is  applied  to  bridges  wMcli  are  cliiefly  supported  by 
one  abutment.  In  relation  to  the  anterior  teeth,  it  consists  in 
attaching  a  dummy  to  an  artificial  crown,  to  replace  an  adjoin- 
ing absent  tooth.  A  bridge  of  this  style  replacing  two  or  three 
of  the  posterior  teeth  is  formed  by  using  two  of  the  teeth  anterior 


Fig.  315. 


"Fio.  317. 


EiG.  316. 


Fig.  318. 


to  it  as  one  abutment,  with  a  saddle  for  the  other.  A  saddle 
is  an  oval-shaped  piece  of  gold,  of  the  form  of  the  gum  and  a  little 
larger  than  the  base  of  the  tooth,  placed  under  the  posterior  tooth 
of  the  bridge. 

Figs.  315  and  316  represent  an  extension  bridge.     A  crown  on 
the  cuspid,  an  all-gold  crown  on  the  bicuspid,  and  a  saddle,  are 
the  abutments.     In  constructing  this  bridge,  the  teeth  forming  the 
172 


KXTEXSloy    JilUDdKS.  173 

abutments  were  first  crowned.  The  crowns  were  then  adjusted 
in  position,  and  an  impression  and  articulation  taken  in  plaster,  in 
which  the  crowns  were  removed.  From  this  impression  a  model 
was  made  of  plaster  and  marble-dust,  and  an  articulation  in  plain 
plaster.  With  the  crowns  in  position  on  the  model  as  in  the 
mouth,  the  bridge  was  then  constructed  by  the  methods  described 
on  page  154.  The  part  of  the  model  oji  which  the  saddle  rested 
was  marked,  and  enough  of  the  surface  of  the  plaster  removed 
to  cause  the  saddle  to  press  tightly  against  the  soft  tissue  when  the 
bridge  should  be  completed  and  inserted  in  the  mouth.  This  can 
also  be  more  accurately  accomplished  by  marking  the  space  the 
saddle  is  to  occupy  on  the  surface  of  the  impression,  and  fitting 
thereto  a  disk  of  thin  sheet  lead  of  from  No.  22  to  30  gauge  as  the 
hardness  of  the  membranes  suggests.  The  space  occupied  by  the 
lead  will  cause  a  proportionate  depression  on  the  model  when 
made.  As  the  edges  of  the  saddle  should  press  more  forcibly 
against  the  tissues  than  the  central  portion,  it  is  well  to  slightly 
scrape  the  plaster  at  the  margins.  In  the  cementation  of  the 
bridge  care  should  be  taken  that  no  particles  of  oxyphosphate  re- 
main under  the  saddle. 

All-gold  crowns  which  are  to  sustain  the  strain  of  an  extension 
bridge  should  be  stiffened  with  solder  so  as  to  possess  great  rigidity. 
If  this  precaution  is  not  taken,  in  some  cases  the  constant  spring- 
ing motion  of  the  extension  bridge  will  gradually  bend  the  gold  of 
the  side  of  the  gold  crown  away  from  the  surface  of  the  natural 
tooth,  and  cause  leakage  by  disintegration  of  the  cement. 

A  shell  crown  on  a  cuspid  can  be  used  as  an  abutment  in  this 
style  of  bridge,  instead  of  excising  the  natural  crown  and  mounting 
an  artificial  crown  on  the  root  for  the  purpose  (Figs.  317,  318). 

Figs.  319  and  320,  321  and  322,  represent  small  extension 
bridges  of  frequent  construction,  the  former  to  repair  losses  in 
the  anterior  portion  of  the  mouth,  the  latter  to  replace  posterior 
teeth. 

Dr.  T.  Fillebrown's  method  of  constructing  a  bicuspid  or  molar 
all-gold  crown  when  the  sides  of  the  natural  tooth  have  not,  for 
some  reason,  been  reduced  in  dimensions  to  that  of  the  cervix,  is 
to  first  form  and  fit  a  full-sized  collar  of  thin  pure  gold,  then  adapt 
and  solder  over  it  a  second  and  narrower  collar  of  thin  22-carat 
gold  plate,  extending  only  from  the  occluding  surface  about  half 


174 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


the  distance  to  the  gum-margin.     The  cap  for  occluding  surface 
is  then  added  in  the  usual  manner.     When  the  finished  crown  is 


Fig.  319. 


Fig.  321. 


Fig.  320. 


Fig    322. 


cemented  in  position,  and  while  the  cement  is  yet  quite  soft,  a 
burnisher  is  passed  around  the  neck  of  the  crown,  and  the  pure 
gold  forming  that  part,  as  represented  by  A,  Fig.  323,  is  brought 
close  against  the  neck  of  the  natural  tooth.  This  method  of  form- 
ing a  gold  crown  may  be  advantageously  practiced  in  these  cases 
of  bridge-work. 

Fig.  324:  shows  a  pin  shell  crown  which  can  be  made  to  support 
a  porcelain  front  representing  a  cuspid  or  bicuspid.     By  forming 


Fig.  323. 


Fig.  324. 


Fig.  325. 


two  grooves,  respectively  in  the  mesial  and  distal  sides  of  the 
natural  tooth,  for  the  reception  of  platinum  pins  passing  through 


EX TESSIO S    li II ID G ES. 


17^ 


the  gTindiiig-siirfacc  of  tlic  cap  and  fastened  with  a  little  solder  on 
the  outside,  great  security  of  attachment  is  obtained  with  a  partial 
cap,  and  without  the  least  exposure  of  gold  (see  Fig.  325).  In  a 
favorable  case  a  cuspid  cap  may  be  formed  on  this  plan  to  support 
a  lateral.  A  third  pin  may  be  necessary  at  the  palatal  side  of  the 
cuspid. 

The  same  result  can  be  obtained,  but  in  a  more  laborious  way, 
by  first  forming  the  grooves  in  the  sides  of  the  natural  tooth,  then 
making  a  collar  of  pure  gold,  about  E"o.  33  gauge,  and  burnishing 
it  well  into  the  grooves,  and  removing  and  flowing  20-carat  gold 
plate  over  the  outer  surface  of  the  collar.  The  grinding-surface 
is  next  added.  The  gold  is  then  removed  from  the  laljial  surface 
of  the  cap  sufficiently  to  expose  the  natural  tooth. 


In  most  cases  where  shell  croAvns  are  used  on  the  upper  jaw,  the 
gold  forming  the  posterior  side  of  the  cap  can  be  brought  round 
slightly  on  the  labial  surface  of  the  tooth  without  being  observable 


176 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


when  viewed  from  the  front;  but  it  must  be  cut  short  at  the  an- 
terior side  and  not  allowed  to  extend  beyond  the  line  of  the  porce- 
lain front  placed  alongside  of  it.  On  the  lower  jaw  the  band 
of  gold  which  extends  across  the  labial  aspect  need  only  be  re- 
moved enough  to  avoid  exposure  in  speaking. 

Figs.  326,  327,  and  328  represent  an  extension  bridge.  The 
anterior  abutment  consists  of  the  six  front  teeth,  which  were  all 
crowned  and  joined  together,  the  pulps  being  preserved  in  the 
incisors.  A  saddle  on  each  side  forms  the  posterior  abutments. 
In  cases  similar  to  this,  when  the  dummies  are  extended  to  such 
an  extreme  distance  posterior  to  the  abutments,  if  antagonizing 
molars  are  present,  a  mere  saddle  is  insufficient  to  equalize  the 
strain,  especially  as  absorption  goes  on  to  some  extent  under  the 
saddle.  An  extension  of  not  over  two  teeth  on  each  side,  resting 
on  a  plate  or  saddle  extending  from  the  cuspids  back  beyond  the 
bridge  teeth  or  dummies,  is  suggested  instead. 


Fig.  329. 


Fig.  330. 


Fig.  331. 


Fig.  332. 


A  Spur  Support  consists  of  a  flange  formed  at  the  end  of  an 
extension  bridge,  affording  support  by  resting  on  the  palatal  wall 
of  either  an  incisor  or  a  cuspid,  or  in  the  sulcus  between  the  cusps 
of  a  bicuspid  or  molar,  as  shown  in  Tig.  329.     Fig,  330  illustrates 


EXTENSION    lilllDdKS.  I'J'J 

a  case  with  a  spur  resting  against  a  cuspid.  In  the  case  repre- 
sented in  Figs.  331  and  332  the  spur  rests  in  an  indentation  in  an 
amalgam  filling  in  the  molar.  This  form  is  termed  a  cantilever 
bridge. 

A  spur  is  best  formed  as  follows:  "When  the  dummies  are 
mounted  on  the  model  ready  for  investment,  adapt  on  that  portion 
of  the  tooth  where  the  spur  is  to  rest  a  piece  of  very  thin  platinum. 
Place  on  the  surface  of  the  platinum,  when  adjusted,  a  still  nar- 
rower piece  of  gold  plate.  Wax  them  in  position  and  invest. 
The  ends  of  the  platinum  and  plate  should  be  left  extending  far- 
ther across  the  tooth  than  will  be  required  for  the  spur,  to  furnish 
a  means  of  retaining  the  metal  in  position  in  the  investment  during 
soldering.  The  wax  should  only  cover  the  portion  of  the  spur  to 
be  soldered. 

In  extension  bridge-work,  the  portion  which  constitutes  the 
bridge  exerts  on  the  abutments,  in  resisting  the  force  of  occlusion, 
an  action  like  that  of  a  lever.  The  ratio  of  the  force  exerted  is 
proportioned  to  the  length  of  the  bridge  or  lever  from  the  abut- 
ment or  fulcrum.  This  principle  must  receive  consideration  in 
the  employment  of  this  form  of  bridge.  A  flange  or  spur  sup- 
port, if  attainable,  should  as  a  rule  be  applied.  More  than  one 
tooth  should  not  be  extended  from  an  abutment  without  ample 
alveolar  support  besides.  When  two  approximal  crowns  support 
an  extension  bridge  tooth  or  dummy,  the  force  is  counterbalanced 
by  the  resistance  of  the  farthest  anchorage  cro^vn  from  the  bridge, 
the  pressure  on  which  is  in  a  direct  line  from  the  socket,  the  ap- 
proximal crown  acting  as  a  fulcrum,  the  force  on  which  is  upward 
in  the  line  of  the  root.  The  occluding  surfaces  of  the  bridge 
teeth  should  be  made  unusually  narrow  from  labial  to  palatal  side,^ 
to  offer  less  occluding  surface  to  those  antagonizing. 


13 


CHAP  TEE    IV. 

BAR  BRIDGES. 

This  style  of  bridge  receives  its  name  from  tlie  fact  that  the 
teeth  or  dummies  forming  it  are  supported  by  bars  anchored  in 
the  natural  teeth  on  either  side  by  means  of  fillings.  Failure 
to  appreciate  its  limitations  and  faults  of  construction  are  re- 
sponsible for  disappointments  in  its  use  which  have  militated 
against  its  more  common  application. 

In  the  first  place,  its  successful  employment  is  confined  to  the 
insertion  of  one,  or  at  most  two  teeth.  An  attempt  to  support 
more  than  two  teeth  by  this  method  will  most  certainly  result  in 
failure. 

The  most  glaring  fault  of  construction  is  insufficient  anchorage 
for  the  bars.     If  the  anchorage  tooth  is  alive,  the  bar  should  ex- 
tend in  a  suitably  shaped  cavity  two-thirds  or  three-fourths  the 
width   of   its   palatal   or   occluding   surface, 
Tig.  333.  according  as  it  is  an  incisor  or  a  cuspid,  or 

/i\  a  bicuspid  or  molar,  and  be  thoroughly  se- 

/  ;j  ;  cured    by    the    filling-material.     Thus     an- 

chored, tlie  bar  is  capable  of  supporting  the 
bridge  and  resisting  the  leverage  exerted  on 
it  in  occlusion  and  mastication,  which  it  can- 
not reliably  do  when  simply  anchored  in  a 
shallow  filling  inserted  in  the  side  of  a  tooth, — an  incorrect  method 
too  often  practiced. 

In  a  pulpless  tooth  the  bar  should  be  bent  and  inserted  into 
the  root-canal,  as  shown  in  Tig.  333. 

In  the  incisors  and  cuspids  the  anchorage  cavities  or  slots  are 
■formed  in  the  palatal  portion  of  the  teeth,  extending  from  the  ap- 
■proximal  surface  contiguous  to  the  space  to  be  bridged,  two-thirds 
to  three-fourths  the  width  of  the  tooth,  and  usually  about  one- 
1-hird  of  its  length  from  the  gingival  margin  (Fig.  334),  direct 
access  into  the  cavities  being  afforded  through  the  palatal  wall. 
178 


BAR  BJillXIKS.  179 

The  slots  or  cavities  having  been  formed,  a  model  of  the  case  is 
made.  Should  the  cavities  to  receive  the  bar  be  imperfectly  rep- 
resented on  the  model,  they  should  be  trimmed  and  shaped  to  cor- 
respond to  those  in  the  mouth.  The  exact  alignment  of  the  porce- 
lain tooth  in  the  mouth  having  been  determined  with  the  aid  of 
wax,  it  should  be  adjusted  on  the  model  and  secured  in  position 
by  a  matrix  of  plaster. 

The  base  of  the  tooth  should  rest  firmly 
on  the  gum,  to  accomplish  which  a  small 
portion  of  the  plaster  should  be  removed 
from  underneath  the  tooth  on  the  model. 

The  bar  is  best  constructed  of  platinum 
or  iridio-platinum  wire,  ISTos.  14  to  16 
gauge.  The  platinum  is  more  easily 
manipulated,  but  affords  less  rigidity, 
which  should  be  considered  where  there 
is  a  close  occlusion.  The  wire  can  be  ex- 
tended in  one  piece  entirely  across  the 

bridge  from  one  anchorage  to  the  other  by  bending,  or  by  remov- 
ing a  portion  of  its  bulk  back  of  the  porcelain  tooth;  or  the  bar 
can  be  cut  and  made  in  two  sections,  if  the  position  of  the  an- 
chorage cavities  so  suggests. 

The  ends  of  the  bar  should  be  flattened  with  a  hammer,  an- 
nealed, and  shaped  as  shown  at  A,  Fig.  334.  The  remainder  of 
the  section  of  the  bar  which  is  to  rest  in  the  cavity  is  best  filed 
on  the  sides,  so  as  to  give  it  a  somewhat  triangular  form,  the 
broad  base  of  which  is  toward  the  bottom  of  the  cavity.  This 
form  favors  the  ready  impaction  of  the  filling-material  which  is 
to  secure  the  bar. 

The  porcelain  tooth  having  been  backed,  the  bar,  whether  in 
one  piece  or  two  sections,  is  attached  to  it  with  wax  cement,  then 
removed  from  the  model  and  soldered.  Enough  gold  should  be 
added  to  properly  contour  the  tooth  and  securely  fasten  the  bar. 

Anchoring  the  Bar. — Gold  and  amalgam  are  the  only  filling- 
materials  suited  for  securing  bars.  Amalgam  is  objectionable 
only  when  the  position  of  the  cavity  renders  it  visible.  Under 
such  circumstances,  however,  the  exposed  portion  can  be  cut  away 
when  set,  and  covered  with  gold.  Fastening  one  end  of  the  bar 
temporarily  with  oxyphosphate,  while  the  other  is  being  secured, 


180  -^  ^ TIFICIA L  CRO  WN-  A ND  BRID G E-  WORK. 

will  sometimes  facilitate  tlie  operation  of  anchoring  with  amalgam, 
but  the  best  plan  is  to  fasten  the  ends  of  the  bar  with  gold-foil 
pellets  and  then  fill  flush  the  remainder  of  the  cavities  with  amal- 
gam. The  amount  of  gold  used  need  only  be  sufficient  to  secure 
the  bridge  against  the  slightest  motion  until  the  amalgam  sets. 

When  the  anchorage  tooth  is  pulpless,  the  end  of  the  bar  which 
extends  into  the  canal  should  be  cemented  first.  Frequently, 
when  bicuspids  and  molars  containing  large  cavities  of  decay  are 
used  for  anchorages,  it  is  advantageous  to  first  insert  the  anchorage 
fillings,  and  then  drill  out  sufficiently  to  admit  the  bar,  which  can 
then  be  secured  with  additional  filling-material. 

When  gold  is  the  filling-material  used,  the  rubber  dam,  which 
must  be  thin,  is  first  adjusted  on  the  natural  teeth,  and  the  bridge 
■then  pressed  to  position  over  it.  In  anchoring  with  gold,  the  best 
way  is  to  first  fill  such  portions  of  the  cavities  as  are  inaccessible 
when  the  bars  are  in  position,  how  far  to  proceed  being  determined 
by  occasionally  trying  in  the  piece  as  the  gold  is  inserted.  The 
bridge  is  then  pressed  to  place,  and  held  firmly  while  the  ends 
of  the  bars  are  secured  by  condensing  around  them  a  few  pellets 
of  foil,  after  which  the  gold  is  carefully  impacted  around  the 
bar,  the  filling  of  one  of  the  cavities  being  carried  to  completion 
before  going  on  with  the  other. 

In  the  preparation  of  the  cavities,  their  sides  should  be  given 
an  undercut  form  with  strong  edges.  When  only  sufficient  tooth- 
structure  has  been  removed  at  the  approximal  portion  to  just  ad- 
mit the  bar,  it  is  a  doubtful  expedient  to  attempt  to  fill  the  narrow 
seam  around  it  with  gold.  In  such  cases,  this  portion  of  the  filling-^ 
is  better  made  with  amalgam,  which  is  inserted  at  the  sides  and 
along  the  floor  of  the  cavity  before  the  bridge  is  fixed  in  position. 
Then,  beginning  at  the  interior  end  of  the  cavity,  gold  can  be  in- 
serted and  gradually  condensed  toward  the  amalgam,  with  which 
it  will  imite  when  brought  in  contact.  Any  surplus  of  amalgam 
can  be  removed  subsequently  when  it  has  set.  Amalgam  placed 
around  the  bar  as  here  described  is  seldom  visible  from  the  labial 
side,  and  the  quantity  required  is  insufficient  to  materially  discolor 
the  tooth. 

In  Bicuspid  and  Molar  Bar  Bridges  the  bar  should  be  carried 
well  across  the  occluding  surface,  and  the  end  bent  and  imbedded 
in  the  line  of  the  sulcus  toward  the  side  opposite  to  that  from 


BAR  BJ{/D(JKS. 


\>6i 


which  the  bar  enters,  as  shown  in  Fig.  335.  Forming  the  end  of 
the  bar  in  this  way  affords  the  greatest  security,  when  it  is  prop- 
erly anchored  with  the  filling-material,  by  preventing  any  rota- 
tory movement,  or  any  loosening  of  the  bar  by  force  applied  in  a 
forward  direction. 

The  principles  involved  and  the  Fig.  335.  . 

method  described  for  shaping  and 
securing  the  ends  of  bars  apply 
equally  well  to  cases  where  one  end 
of  the  bridge  is  supported  by  a  bar 
and  the  other  by  an  artificial  crown, 
as  has  been  previously  illustrated. 

An  Extension  Bar  Bridge. — In  this  form  of  bridge  the  artificial 
(dummy)  tooth  is  supported  by  a  bar  anchored  in  a  natural  tooth 
at  one  end  only.  At  the  other  end  of  the  bridge  the  bar  is 
either  made  in  the  form  of  a  spur  to  rest  against  the  adjoining 
natural  tooth,  or  it  is  not  extended  beyond  the  dummy. 

In  the  case  represented  in  Fig.  336,  an  upper  cuspid,  the 
patient,  a  lady,  declined  to  have  the  bicuspid  capped  or  crowned 
in  any  way  for  the  purpose  of  sup- 
porting the  cuspid.  The  posterior 
approximal  side  of  the  bicuspid  at  the 
time  contained  a  large  filling.  This 
filling  was  removed,  and  a  cavity  of 
proper  shape  to  receive  a  bar  was  ex- 
tended forward  from  it  between  the 
cusps  to  the  anterior  side.     A  suitable 

bar  for  the  cavity  was  formed  to  support  the  cuspid  in  the  man- 
ner illustrated  at  A  and  B.  The  angular  form  (C)  given  the  bar 
rendered  it,  when  anchored  with  the  filling-material,  very  secure, 
and  fully  capable  of  supporting  the  cuspid. 

The  filling-material,  which  was  gold,  occupied  most  of  the 
space  of  the  occluding  surface  between  the  cusps.  The  occluding 
tooth  was  trimmed  off  proportionately.  A  spur  extended  from  the 
anterior  side  of  the  artificial  tooth  resting  on  the  lateral  incisor. 
The  occlusion  was  favorable  to  the  insertion  of  the  bridge  tooth 
in  the  form  presented,  and  it  had  been  comfortably  and  satisfac- 
torily worn  for  ten  years  when  last  seen.  When  examined  it 
showed  no  change,  except  that  the  force  of  occlusion  on  the  cuspid 


Fig.  336. 


182  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

had  slightly  bent  the  bar  and  caused  the  tooth  to  assume  a  deeper 
position  in  the  jaw  than  at  the  time  it  was  inserted,  though  this  was 
only  to  the  extent  of  the  absorption  of  gum-tissue  under  the  bridge. 
In  some  instances  the  bar  of  a  bridge  of  this  kind  can  be  ex- 
tended across  the  occluding  surfaces  of  two  teeth,  and  additional 
support  thus  obtained. 

Cast  Inlays  or  Fillings,  as  described  on  page  127,  can  be  used 
in  some  instances  to  support  the  end  of  a  bar.  In  such  a  case,  a 
short  piece  of  wire  to  form  the  bar  is  inserted  in  position  in  the  wax 
in  the  matrix  of  platinum  before  it  is  removed  from  the  cavity,, 
and  soldered  in  it.  The  wire  permits  the  inlay  to  be  removed  in 
position  at  the  end  of  the  bridge.  The  attachment  of  the  bridge 
is  then  made  to  the  bar  or  inlay. 

The  practical  application  of  bar  bridge-work  is  limited.  It 
frequently  affords  advantages  for  artificial  restoration,  in  many 
cases  Avhere  a  single  tooth  has  been  lost,  not  presented  by  other 
methods.  Its  practical  success  depends  chiefly  upon  the  character 
of  its  supports  and  the  skillf  ulness  with  which  it  is  anchored. 


CHAPTEK    V. 

PAIITIAL   CAP   AND    PIN    BltlDGE. 

This  style  of  bridge  is  used  only  in  case  of  loss  of  a  single  front 
tooth. 

Fig,  337  represents  a  typical  case,  in  which  a  lateral  incisor 
(crown  and  root)  had  been  lost,  the  cuspid  and  central  incisor, 
fully  vitalized,  and  without  approximal  carious  cavities,  remain- 
ing in  position. 

Fig.  337. 


To  Make  a  Pin  mid  Plate  Bridge} — 1.  Take  in  plaster  an  ac- 
curate impression.     From  this  obtain  a  plaster  model  of  the  parts. 

2.  Make  from  pure  gold,  rolled  to  the  thinness  of  l^o.  26, 
standard  gauge,  base-plates,  to  .be  carefully  adjusted  to  the  palato- 
approximal  surfaces  of  the  cuspid  and  incisor.  These  can  be 
made  by  swaging  on  dies  and  counter-dies  obtained  from  the 
model,  but  more  conveniently  by  bending  the  gold  into  shape 
upon  the  plaster  model  and  pressing  and  burnishing  it  into  per- 
fect adaptation  upon  the  natural  teeth. 

3.  Select  a  plain  plate  porcelain  tooth  of  suitable  length  that 
will  fit  easily  into  the  interspace;  back  with  gold  or  platinum; 
adjust  in  position  to  the  gold  base-plates  on  the  model,  and  attach 
with  wax  cement.  Remove  and  fit  in  the  mouth,  and  chill  with 
ice-water.  IText  remove  from  the  mouth,  invest,  and  solder  tooth 
and  plates  together,  as  shown  in  Fig.  338. 

1  Dr.  W.  F.  Litch,  Dental  Cosmos,  vol.  xxviii,  No.  3. 

188 


184 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


4.  Tor  the  purpose  of  attaching  the  denture  as  thus  far  con- 
structed, drill  a  small  cylindrical  opening  through  the  palatal 
surface  of  the  enamel  of  the  cuspid  and  incisor  respectivelv. 
These  openings  should  usually  be  placed  about  as  indicated  in 
Fig.  340j  at  C,  D.     Sometimes,  owing  to  a  close  occlusion  or  to 


Fig.  338. 


Fia.  339. 


Fig.  340. 


the  contour  of  the  tooth,  it  is  desirable  that  they  should  be  located 
a  trifle  nearer  the  neck  of  the  tooth.  Each  opening  should  be 
well  undercut,  but  must  not  encroach  upon  the  dentin  far  enough 
to  endanger  the  pulp.  In  size  the  openings  need  not  be  larger 
than  will  admit  a  platinum  pin-head,  in  diameter  corresponding 
to  ISTo.  13,  standard  gauge,  with  a  shank  of  ISTo.  18,  standard  gauge. 
Into  each  of  these  openings  must  be  fitted  a  platinum  pin  of  the 
size  indicated.  The  head  of  each  pin  must  be  made  thin  and 
perfectly  flat  both  upon  its  upper  and  under  surfaces. 


/'.urn. I/.  (A I'  AM)  i'i.\  HuiijiiE.  185 

5.  In  each  of  the  Ijase-plates  make  an  opening  corresponding 
in  position  to  those  in  the  natural  teeth.  Pass  through  these 
openings  and  cement  in  them  the  free  ends  of  the  platinum  pins. 
While  the  cement  is  yet  plastic,  place  the  denture  in  position  in 
the  mouth,  carefully  pressing  the  pin-heads  into  the  openings 
made  for  them,  and  burnishing  the  base-plates  into  perfect  con- 
tact with  the  palatal  surfaces  of  the  teeth;  chill  the  cement,  re- 
move and  invest.  Next  attach  the  pins,  and  also  flow  solder  over 
the  surface  of  the  base-plates  to  stiffen  them. 

Fig.  338  represents  the  appliance  without  the  pin.  A  is  the 
porcelain  tooth  and  backing;  E,  the  base-plates;  C  and  F,  the 
openings  for  the  pins. 

Fig.  339  represents  the  appliance  completed  with  the  pins  in 
position. 

Fig.  340  represents  the  natural  teeth  and  interspace  B,  Avith 
openings  for  retaining-pins,  C,  D. 

Fig.  341  represents  the  appearance  presented  when  the  bridge 
is  cemented  in  position. 

The  bridge  is  attached  by  cementing  in  position  with  oxy- 
phosphate. 

When  the  supporting  teeth  have  vital  pulps  and  very  sensitive 
dentin,  the  difficulty  of  securing  reliable  anchorage  for  each 
of  the  plates  seriously  militates  against  this  method.  Loosening 
of  the  bridge,  especially  in  "close  bites,"  is  apt  to  occur  at  the 
most  inopportune  moment,  demanding  its  immediate  re-cementa- 
tion. Practical  experience  by  the  author  in  the  use  of  this  form 
of  attachment  shows  that  two  pins  in  one,  if  not  in  each,  of  the 
plates  are  necessary.  The  exception  is  a  pulpless  tooth,  which  ad- 
mits of  considerable  lengthening  of  a  single  pin. 


CHAPTEE    VI. 

EEMOVABLE  AND  KEPLACEABLE  POKCELAIN  FKONTS. 

In  those  forms  of  crown-  and  bridge-work  in  whicli  porcelaiii 
fronts  are  used  there  is  some  liability  of  fracturing  the  fronts, 
either  in  the  soldering  processes  connected  with  the  construction, 
or  subsequently,  after  the  insertion  of  the  piece  in  the  mouth,  by 
the  patient  in  mastication.  The  replacing  of  a  porcelain  front 
after  the  work  has  been  permanently  fixed  in  position  is  fre- 
quently attended  with  great  difficulty,  and  the  result  is  often  un- 
satisfactory or  doubtful  regarding  its  permanency.  The  desire 
to  obviate  such  difficulties  has  prompted  the  introduction  of  vari- 
ous methods  of  construction  in  which  the  porcelain  fronts  are 
removed  from  their  positions  previous  to  the  soldering  processes, 
and  afterward  adjusted  so  as  to  be  easily  replaceable  by  means 
of  duplicates  in  case  of  fracture  when  the  work  is  being  worn 
in  the  mouth.  These  methods  applied  to  a  bar  bridge  afford 
access  to  the  cavities  of  anchorage. 

A  modification  of  Dr.  I.  F.  Wardwell's  method,  which  is  simple 
in  construction  and  application  in  comparison  with  most  forms 
in  use,  is  as  foUow^s:  A  thick,  narrow  piece  of  18-carat  gold  plate, 
at  least  ISTo.  18  standard  gauge,  is  soldered  to  the  tooth,  and  its 
two  sides  undercut  with  a  very  thin  separating  file  (Figs.  342,  343). 
A  very  thin  piece  of  platinum,  covering  the  entire  back  of  the 
tooth,  is  burnished  against  it,  well  into  the  undercut  sides,  the 
platinum  being  annealed  several  times  during  the  operation.  The 
platinum  is  held  in  a  flame  while  a  small  quantity  of  pure  gold 
is  flowed  over  the  outer  surface  and  then  refitted  to  the  back  of 
the  tooth,  to  which  it  is  again  burnished.  This  operation  is  re- 
peated until  the  platinum  and  gold  form  a  moderately  light  back- 
ing which  fits  perfectly.  The  platinum  surface  is  then  covered 
with  investing  material,  and  on  the  other  side  18-  or  20-earat 
gold  plate  flowed  until  a  suitable  thickness  is  obtained.  When 
trimmed  into  proper  shape  and  attached  to  the  bar,  this  forms  a 
186 


RKMOVAUIJ-:  AND  liKI'LACKABLh:  I'OIKIlf.A  I S  FUO.\TS.     Jyj 


substantial  backing  or  socket  (Fig.  344),  in  which,  when  the  bar 
is  anchored,  the  porcelain  tooth  can  be  fastened  with  a  little  oxy- 
phosphate  cement  or  gutta-percha  (Fig.  345).-' 


Fig.  342.  Fio.  343. 


Fig.  344. 


Fig.   34.5. 


Fig.  346. 


Fig.  347. 


Any  ordinary  porcelain  front  to  a  bicuspid  or  molar  dummy 
can  be  made  on  the  removable  or  replaceable  plan,  by  backing 
the  porcelain  in  the  usual  manner  with  gold  or  platinum  plate 
without  bending  the  pins,  adjusting  the  gold  cap  in  position,  at- 
taching the  cap,  and  backing  with  wax  cement,  then,  removing 
the  porcelain  front  (Fig,  346),  investing  and 
soldering  the  cap  and  backing  together.  The 
backing  must  be  made  thick  with  solder,  the 
holes  in  it  deepened  with  a  drill,  and  the  pins 
of  the  porcelain  front  serrated  and  fitted  therein. 
After  the  final  soldering,  the  porcelain  fronts 
are  cemented  in  position  with  oxyphosphate. 

Dr.  C.  L.  Alexander's  method  is  to  use  teeth 
having  long  pins,  as  in  Fig.  347.  The  facings 
are  fitted  in  proper  position  and  cemented  with 
hard  wax.  The  wax  around  the  pins  is  then 
heated  with  the  points  of  a  hot  instrument,  and  the  facings  are 
removed  without  disturbing  the  backings.  Half-inch  pieces  of 
fine  iron  binding-wire  are  bent  to  form  staples.,  their  ends  heated 
and  pushed  through  the  pin-holes  from  the  facing  side  in  the 
backings,  leaving  a  loop  on  that  side  and  projecting  ends  on  the 
other,  which  are  twisted.     The  wax  is  removed  from  the  backings 

1  Dr.  F.  T.  Van  "Woert  has  introduced  pliers  with  combination  points  which 
much  simplify  the  construction  of  a  socket  of  this  form  and  the  replacement  ot 
the  porcelain  front  in  case  of  fracture  by  the  patient. 

Porcelain  fronts  or  dummies  of  the  character  described  with  the  backing  baked 
in  the  porcelain  of  the  tooth  can  now  be  purchased  ready-made  under  the  name 
of  "Mason's  Detachable  Tooth." 


188 


ARTIFIGIAL  CROWN-  AND  BRIDGE-WORK. 


and  little  ferrules  of  pure  gold  placed  around  tlie  pin-holes  (Fig. 
348).  Hard  wax  is  next  applied  on  the  outside  of  the  ferrules, 
the  ends  of  the  iron  wire  brought  down  to  hold  them  in  position, 
and  the  inside  of  the  ferrules  filled  with  investing  material.  Fig. 
349  shows  an  invested  case  ready  for  the  soldering  process,  which 


Fig.  348. 


Fig   340. 


will  unite  the  ferrules  to  the  backings,  and  at  the  same  time  join 
the  backings  to  each  other  and  properly  shape  them.  When  sol- 
dered and  trimmed,  the  facings  are  put  in  place  with  a  very  thin 
oxyphosphate  cement  between  fronts  and  backings,  the  pin  ends 


Fig.  3.50. 


are  bent  down  on  the  backing  within  the  ferrules,  and  the  ferrules 
filled  with  amalgam  packed  moderately  dry.  The  bridge  is  then 
put  aside  until  the  amalgam  has  set,  when  it  is  ready  for  insertion. 
Fig.  350  shows  a  central  crowii  ready  to  receive  the  porcelain 
front,  and  a  piece  of  bridge-work  with  the  cuspid  ferrule  chambers 
as  yet  unfilled. 


CHAPTEE    VII. 

GENERAL  APPLICATION  OF  CROWN- AND  BRIDGE-WOKK. 

The  construction  and  general  application  of  bridge-work,  as 
explained  in  the  foregoing  chapters,  are  additionally  explained 
and  illustrated  in  applying  them  to  the  following  typical  cases: 

Central  or  Lateral  Incisors,  Cuspids  or  Bicuspids. — Figs.  351, 
352  illustrate  a  method  of  replacing  a  superior  central  or  lateral. 
The  central  or  lateral  is  formed  with  a  base  of  gold  or  platinum 


Fig.  35L 


Fig.  352. 


resting  closely  on  the  gum.  A  gold  cap-crown  on  the  first  bi- 
cuspid is  used  to  support  it  in  position  by  means  of  an  iridio-plati- 
num  bar.  A  small  spur  placed  on  the  mesial  side  of  the  bridge- 
tooth  is  suggested  in  such  cases. 

Figs.  353,  354  show  a  case  in  which  two  centrals  are  sup- 
ported in  position  by  bars  extending  from  gold  crowns  on  bicus- 
pids. The  method  of  construction  in  these  cases  is:  First  cap  the 
bicuspids;  then  fit  and  back  the  bridge-tooth  or  teeth  and  fasten 
in  position  in  the  mouth  with  hard  wax.  !N^ext  take  a  plaster  im- 
pression. Remove  and  make  plaster  and  marble-dust  model,  show- 
ing teeth  and  crowns  in  position.  Mark  and  slightly  groove  the 
line  of  the  bar  on  the  model.  Fit  the  bar  in  position  in  groove, 
and  wax  ends  to  cap  and  tooth.  Fasten  the  center  of  the  bar  and 
cover  the  teeth  and  caps  with  investing  material,  and  solder  bar 
or  bars  and  cap  or  caps  together. 

189 


190 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Figs.  355  and  356  illustrate  a  metliod  of  construction  wliicli  will 
avoid  the  exposure  of  gold,  and  also  the  presence  of  a  bar  against 
the  membrane  of  the  gum.  A  shell  crown  is  constructed  as  de- 
scribed on  page  174,  Fig.  325,  for  the  bicuspid.     The  crown  is 


Fig.  353. 


Fig.  354. 


placed  on  the  tooth,  the  lateral  adjusted  and  cemented  in  position, 
an  impression  taken,  and  a  model  made  as  described  in  the  con- 
struction of  case  illustrated  by  Figs.  351  and  352.  On  the  model 
having  the  crown  and  lateral  in  position,  a  flat  bar  is  formed  be- 


FiG.  355. 


Fig.  356. 


tween  the  cuspid  and  lateral  across  the  palatal  section  of  the  cuspid 
to  connect  and  support  the  lateral.  This  bar  is  made  by  first  fit- 
ting across  the  palatal  side  of  the  cuspid,  a  piece  of  thin  platinum 
plate  touching  the  gold  crown  and  backing  of  the  lateral.  Over 
the  platinum  is  placed  a  still  narrower  piece  of  gold  plate  (clasp- 
gold  preferred).     These  are  waxed  at  the  ends  to  the  cap  and 


GKNKIL  \L  A  I'l'L  IC.  I  TION  OF  (  IK)  WN-  .  1  A'Z>  BR  I IX 1 K-  H  ■(>I{K.   \(j\ 

lateral,  and  held  in  position  in  the  center  with  investing  material. 
"When  the  ends  have  been  attached  with  the  solder  to  the  cro^vn 
and  lateral,  the  investment  material  is  removed  from  the  center 
and  the  solder  is  then  flowed  across  the  bar.  This  forms  a  bar  with 
a  surface  of  platinum  to  rest  against  the  tooth. 

Fig.  357  shows  the  form  of  bridge-work  suitable  for  replace- 
ment of  one  or  two  inferior  incisors.  The  labial  section  of  the 
shell  crowns  which  form  the  support  for  the  artificial  tooth  should 
be  removed  only  sufficient  to  avoid  any  considerable  exposure  of 
the  gold  in  the  movement  of  the  lips. 

Other  cases  illustrating  methods  for  single  centrals  and  laterals, 
cuspids  and  bicuspids,  are  shown  in  Figs.  317,  319,  321,  324,  330, 
334,  336,  and  345. 

Fig.  358  explains  and  illustrates  a  method  of  restoring  an  in- 
cisor and  supporting  the  adjoining  loosened  teeth  with  succes- 
sive cemented  connecting  collars  of  gold  in  cases  of  pyorrhea  alve- 

FiG.  357.  Fig.  358. 


Claris.  When  the  natural  teeth  are  all  present,  but  very  loose 
from  this  disease,  connecting  the  teeth  together  with  a  succession 
of  bands  steadies  each  tooth  in  its  socket  and  consequently  permits 
of  much  more  effectual  treatment.  For  the  application  of  such 
collars  the  teeth  generally  need  to  be  slightly  separated.  The  col- 
lars may  be  formed  of  a  strip  of  pure  gold  plate,  about  !N"o.  32  to 
33  gauge,  by  bending  and  fitting  the  strips  to  the  forms  of  any  two 
teeth  in  the  shape  shown  in  Fig.  359,  A.  This  leaves  but  one 
thickness  of  the  plate  between  the  teeth.  An  additional  loop  can 
then  be  added  as  shown  at  B,  for  one  adjoining  tooth.  All  the 
soldering  can  be  done  quickly  with  the  Bunsen  burner  without  in- 
vesting. 

Centrals,  Laterals,  or  Cuspids  ComUned. — Two  laterals  sup- 
ported by  two  central  crowns  are  illustrated  in  Figs.  360,  361. 
Spurs  might  be  additionally  formed  on  the  laterals  to  rest  on  the 


192 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


cuspids.  When  approximal  crowns,  as  in  this  case,  are  united  to 
support  bridge-work,  a  free  space  should  be  preserved  at  the  neck 
between  their  respective  collars  to  admit  the  gum  septa. 


Fig.  360. 


Fig.  361 


Figs.  362,  363,  364,  and  365  show  a  bridge  of  the  incisors  sup- 
ported by  two  collar  crowns  on  the  cuspid  roots.  Shell  crowns 
can  also  be  used  for  this  purpose,  according  to  the  preference  of 
the  operator.  Figs.  366,  367,  and  368  illustrate  a  case  with  shell 
crowns  for  supports.  In  its  construction  the  best  method  of  pro- 
cedure is  to  form  and  fit  the  caps  or  crowns  to  the  cuspids,  re- 
move them  in  plaster  impression  and  bite,  make  models,  and 
then  bridge  between  the  shell  caps  or  crowns  with  the  incisors. 
The  edges  of  the  bands  of  these  shell  caps  should  be  beveled 
and  burnished  close  to  the  teeth.  If  properly  done  they  will 
resemble  gold  fillings.  When  these  shell  caps  become  loose  from 
disintegration  of  the  cement  they  should  be  immediately  reset. 
It  would  be  well  if  cases  of  this  style  could  be  removed  once  a 
year  and  re-cemented.  Other  cases  of  this  character  are  illus- 
trated in  Figs.  288  and  305. 

Cuspid,  Bicuspids,  and  Molars  Combined.- — Figs.  369  and  370 
show  bridge-work  supported  by  cuspid  and  molar  cap  or  crown. 
If  the  cuspid  contains  a  living  pulp  the  natural  crown  should 
be  preserved,  and  an  all-gold  or  shell  crown  should  be  used  in 
preference  to  the  form  illustrated.  Figs.  314  and  315  illustrate 
other  cases. 


GENERAL  APPLICATION  OF  CROWN-  AND  BRIDGE-WORK.  193 


Fig.  362. 


Fig.   rSHS. 


Fig.  364. 


Fig.  365. 


14 


194 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Bicuspids  and  Molars  Combined. — Fig.  3Yl  represents  a  bridge 
on  the  lower  jaw  from  the  first  bicuspid  to  the  second  molar.  The 
inclination  of  the  teeth  toward  each  other  suggests  the  construc- 
tion of  the  bridge  in  the  form  illustrated.  The  molar  is  covered 
entirely  with  a  cap,  the  bicuspid  only  on  the  occluding  surface, 

Fig.  366. 


Fig.  367. 


Fig.  868. 


with  the  gold  extending  only  half  down  the  coronal  section  of 
the  natural  crown  (A).  A  pin  inserted  in  the  cap  fitting  a  hole 
■drilled  in  the  sulcus  of  the  occluding  surface  of  the  bicuspid 
Avill  secure  this  cap  in  position.  This  method  is  very  suitable  to 
a  case  where  the  crown  of  the  bicuspid  is  long  and  the  root 
slightly  exposed.  Molars  under  similar  circumstances  can  be 
capped  for  bridge-work  in  like  manner. 


OENEA'AL  AI'PLK'ATKjN  OF  CROWN-  AND  BRWfiK-WOHh'.    195 

Fig.  809. 


Fig.  370. 


Fig.  371. 


196 


ARTIFICIAL  CROWN-. AND  BRIDGE-WORK. 


Fig.  372  illustrates  a  case  of  bridge-work  supported  by  cast  fill- 
ings on  an  abraded  bicuspid  and  molar.  It  will  be  noticed  that 
tbe  molar  tips  forward  considerably. 


Fig.  372. 


"Fig.  373  represents  a  practical  case  in  wliicli  the  upper  third 
molar  and  the  first  bicuspid  (both  without  antagonizing  teeth) 
were  utilized  for  the  attachment  of  a  bridge  made  of  gold  crowns 
with  porcelain  facings,  to  supply  the  loss  of  the  intervening  teeth.-^ 

Fig.  373. 


"Fig.  374  represents  the  case  as  prepared  for  the  bridge.  A, 
the  inner  cusp  of  the  bicuspid  cut  down  to  allow  the  placing  of 
a  sufficiently  thick  crown-plate;  B,  a  cylindrical  undercut  open- 
ing between  the  cusps  for  a  retaining-pin ;  C,  the  third  molar, 
made  uniform  in  size  from  neck  to  grinding-surface,  the  latter 
also  being  considerably  retrenched;  D,  the  crown-plate  of  a  par- 
tial cap,  made  of  pure  gold,  soldered  with  20-carat  gold,  and  so 
constructed  as  to  cover  every  portion  of  the  tooth  except  its  buccal 
surface,  the  free  edge  passing  up  under  the  gum;  E,  a  retaining- 
pin  adapted  to  the  opening  B ;  F,  the  gold  cap  for  the  molar. 

"Fig.  375  represents  the  bridge  anchored  in  position  with  oxy- 
phosphate  cement. 

'Dr.  W.  F.  Litch. 


GENERAL  APPLICATION  OF  CROWN-  AND  IJRWaE-WORK.   197 


''In  the  above  case  it  will  be  observed  that  there  is  a  considerable 
space  between  the  bicuspid  and  cuspid.     This  made  it  readily 


Fio.  374. 


practicable  to  give  so  considerable  a  thickness  to  the  mesial  wall 
of  the  partial  cap  as  to  hold  it  securely  against  the  side  of  the 
tooth.  Had  the  space  been  less,  contact  with  the  cuspid  would 
have  afforded  the  desired  security. 

'Tig.  376  represents  another  case  in  which  a  bridge  was  at- 
tached by  a  bar,  partial  cap,  and  retaining-pin.  A  is  an  upper 
second  bicuspid  (without  antagonist) ;  B,  its  inner  cusp,  cut  down ; 
C,  opening  for  retaining-pin;  D,  second  molar,  with  slot  for  bar; 
E,  cuspid;  F  represents  the  partial  facing;  G,  the  retaining-pin; 
H,  a  molar  crown  of  gold,  with  porcelain  front ;  I,  a  platinum  bar 
attached  to  the  crown  (H)  and  made  to  fit  into  a  slot  (at  D);  J, 
a  plain  plate  cuspid,  heavily  backed  and  strongly  soldered  to  the 
partial  cap,  but  left  without  attachment  to  or  contact  with  the 
cuspid. 

"Fig.  377  shows  the  Ijridge  anchored  in  position. 

"This  case,  after  two  years  of  wear,  was  still  in  perfect  con- 


198 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


dition  and  doing  good  service.  As  it  was  possible  to  keep  the 
gold  attachments,  backings,  etc.,  out  of  sight,  the  appearance  pre- 
sented is  very  natural. 

Fig.  376. 


"The  absence  of  antagonizing  teeth  for  the  bicuspids  in  each 
of  these  cases  was  a  favorable  condition,  as  a  considerable  thick- 
ness could  be  given  to  the  crown-plate  without  any  interference 
with  occlusion.     When  the  conditions  are  not  so  favorable,  cut- 


FiG.  377. 


ting  down  the  inner  cusp  to  the  required  extent  and  sinking  the 
opening  for  the  retaining-pin  to  the  necessary  depths  are  processes 
certainly  to  be,  as  a  rule,  preferred  to  the  entire  removal  of  the 
crown  for  the  purpose  of  f erruling  the  root  for  the  mounting  of  a 
crown  of  gold  and  porcelain, — a  procedure,  however,  not  by  any 
means  to  be  indiscriminately  denounced,  for  in  many  cases  it  is 
in  the  highest  degree  advisable. 

"There  is  this  fact  to  be  considered  in  regard  to  the  use  of  the 
partial  caps  here  figured, — that  many  patients  can  be  induced  to 
consent  to  their  employment  who  would  refuse  to  submit  to  more 
radical  measures,  and  thus,  even  when  the  latter  would  be  ad- 
visable, the  former  may  be  employed  as  a  compromise,  or  even 


GENERAL  APPLICATION  OF  CROWN-  AND  BRIDGE-WORK.   199 

as  a  temporary  expedient.  Having  once  tested  the  advantage 
of  a  well-fitting  bridge,  the  wearer  is  much  more  likely  to  consent 
to  whatever  measures  are  necessary  to  give  it  security  and  per- 
manence." 


Fig.  378. 


Fig.  379. 


Incisors,  Cuspids,  Bicuspids,  and  Molars  combined. — Figs. 
378  and  379  represent  a  piece  of  bridge-work  extending  from  a 
central  incisor  to  a  molar.  In  such  a  case  the  best  method  of  pro- 
cedure usually,  and  specially  the  one  most  likely  to  prevent  misfit 
from  warping,  is,  construct  the  front  section,  consisting  of  the 
central,  lateral,  and  cuspid;  next  form  the  molar  cap.  Fit  the 
molar  cap  and  front  section  of  the  bridge  in  position  in  the  mouth, 
remove  in  plaster  impression  and  bite,  and  construct  the  bicuspid 
and  molar  dummies  between  the  cuspid  crown  and  molar  gold 
cap.  In  a  bridge  of  this  character,  if  the  natural  cuspid  is  intact, 
a  shell  crown  may  be  used.     Fig.  380  gives  the  palatal  view  of  a 

Fig.  380. 


piece  of  bridge-work  consisting  of  a  gold  cap  on  the  molar  and 
shell  cap  on  the  crown  of  the  cuspid,  supporting  a  single  bicuspid 
and  a  lateral  incisor.  Fi 
principle. 


303  illustrates  bridge-work  similar  in 


200 


ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 


EXTENSIVE  APPLICATIONS  OF   CROWN-  AND  BRIDGE-WORK. 

The  following  illustrations  of  cemented  bridge-work  bj  Dr. 
H.  A.  Parr  show  extreme  cases  in  the  way  of  large  operations 
in  which  the  system  has  been  applied. 

Figs.  381,  382,  383,  and  38i  represent  a  case  in  which  the 
roots  of  the  two  superior  centrals,  a  partially  decayed  right  first 
molar,  and  a  badly  decayed,  pulpless  left  first  molar  were  all  that 
remained  of  the  upper  natural  teeth.  On  the  two  central  roots 
were  mounted  collar  crowns,  and  on  the  two  molars  all-gold  cap- 
crowns.  These  four  crowns,  acting  as  abutments  for  the  bridge 
denture,  bore  between  them,  proportionately  on  each  side,  the 
force  and  leverage  of  occlusion.  The  contour  of  the  arch  in  the 
region  of  the  cuspids  was  restored  by  a  skillful  and  artistic  placing 
of  the  artificial  teeth,  which  are  prominent  and  long. 

Tigs.  385,  386,  387,  and  388  represent  a  case  in  which  two 
large  and  firm  superior  cuspid  roots,  and  a  right  pulpless  molar, 
with  a  saddle  on  the  left  side,  support  a  large  bridge. 

In  the  case  illustrated  by  Figs.  389  and  390,  two  superior  molars 
and  a  second  bicuspid  on  the  right,  and  a  first  bicuspid  and  a  saddle 
under  the  "dummy"  representing  the  first  molar  on  the  left  side, 
form  the  abutments.  Prior  to  the  insertion  of  the  bridge-work, 
the  patient  had  worn  artificial  teeth  on  a  plate.  The  advisability 
of  extensive  permanently  cemented  bridge-work,  such  as  is  illus- 
trated in  this  and  the  case  illustrated  in  Fig.  386,  is  questionable. 
The  permanency  of  the  latter  probably,  and  most  certainly  that  of 
the  former,  cannot  be  assured. 

The  lateral  force  of  mastication,  exerted  on  the  bridge,  will 


Tig.  381. 


EXTENSIVE  Al'I'LICATIONS  OE  CROWN-  AND  BRID(JE-\['(jRK.   201 

Fig.  382. 


Fig.  383. 


Fig.  384. 


202 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 
Fig.  385. 


Fig.  387. 


Fig.  388. 


EXTENSIVE  APPLICATIONS  OF  CROWN-  AND  BRIDd E-WORK.  203 

especially  affect  the  side  on  which  the  saddle  is  used,  and  in  time 
is  certain  to  loosen  and  destroy  the  abutments.  Cases  such  as 
these,  where  the  bridge  is  so  extensive  and  the  abutments  so  few, 
are  more  properly  served  by  inserting  what  are  termed  removable 
plate  bridges,  which  have  alveolar  support  in  addition  to  the  abut- 
ments. The  insertion  of  bridge-work  in  cases  of  this  character  to 
avoid  the  presence  of  a  plate  can  only  be  regarded  as  a  temporary 
expedient  to  afford  a  respite  from  that  annoyance.  It  is  therefore 
an  expedient  not  to  be  indorsed,  as  the  patient  in  a  short  time  will 
again  have  to  resort  to  a  plate  and  again  experience  the  initiatory 
unpleasantness  attending  its  insertion. 

In  the  bridge-work  illustrated  in  Figs.  391,  392,  and  393, 
crowns  on  a  second  bicuspid,  a  pulpless  molar,  and  the  roots  of 
a  cuspid  and  lateral  constitute  the  abutments. 

Fig.  389. 


Fig   390 


204 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 


Fig.   391. 

{    \    r'''''M    'V- 


i^  \ 


Fig.  392. 


Fig.  393. 


EXTENSIVE  APPLICATIONS  OF  CROWN-  AND  BRIDGE-WORK.   205 

Fig.  394. 


Fig.  395. 


Figs.  394  and  395  illustrate  an  extensive  case  of  artificial  re- 
j)lacement  by  crowning  and  bridging  operations.  Fig.  394  repre- 
sents the  case  as  presented  for  treatment.  The  few  remaining 
superior  and  inferior  natural  teeth  had  no  corresponding  antago- 
nists, which  caused  the  interlocking  and  abnormal  condition  in 
regard  to  occlusion  shown.  The  superior  right  bicuspid,  the  left 
central,  and  the  left  cuspid  were  crowned,  the  bicuspid  being  short- 
ened and  the  cuspid  lengthened  in  the  operation.     The  intervening 


206 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


lateral  root  between  the  central  and  cuspid,  having  been  treated 
and  filled,  was  allowed  to  remain.  With,  the  three  crowns  to 
serve  as  abutments  the  intervening  spaces  were  bridged  with 
artificial  teeth,  the  extension  on  the  left  side  being  supported  by  a 
saddle.  The  spaces  between  the  inferior  cuspids  and  molars  on 
both  sides  were  bridged,  the  bicuspid  on  the  left  supporting  the 
bridge,  instead  of  the  cuspid,  as  on  the  right;  the  left  cuspid  was 
crowned  and  the  incisive  edges  of  the  incisors  trimmed  even. 

Fig.  395  illustrates  the  finished  case,  and  shows  the  complete 
artificial  restoration  of  the  parts. 

Fig.  396. 


Figs.  396  and  397  represent  a  case  in  which  crown-  and  bridge- 
work  has  been  extensively  applied.  The  occluding  surfaces  of 
the  teeth  were  affected  with  abrasion.  Gold  crowns  with  porce- 
lain fronts  which  presented  laterally  the  form  illustrated  in  Fig. 
396  were  mounted  on  the  incisors  and  cuspids,  the  pulps  of  which 
were  preserved.     The  posterior  teeth  were  crowned  with  all-gold 


KXTEysiVK  .\i'i'Li(j.\'n(>.\s  (>i-  (:i>,<)WS-  amj  i'.i:U)'ii:-\v<jiii<.  207 


crowns.     The  missing  teeth,  except  those  on  the  inferior  left  side, 
were  artificially  restored  with  bridge- work. 


Fig.  Z'.n 


Permanently  cemented  bridge-work  of  the  extensive  style  illus- 
trated in  some  of  these  cases  is  now  seldom  practiced.  Remov- 
able forms  affording  alveolar  support  are  adopted  in  preference. 
TVTiere  the  abutments  are  numerous  and  offer  suitable  supports  to 
permit  the  bridge--work  to  be  constructed  in  sections  around  the 
arch,  permanently  cemented  bridges  are  permissible. 


CHAPTEK    VIII. 

EEPAIK  OF  CKOWN-  OK  BKIDGE-WOEK. 

The  fracture  of  a  porcelain  front  to  a  permanently  attached 
bridge  is  an  annoying  incident  for  both  patient  and  dentist.  It 
is  usually  attributable  to  failure  to  properly  protect  the  incisive 
edge  or  occluding  surface  of  the  porcelain  with  metal,  a  precau- 
tion rendered  necessary  by  the  rigid  character  of  the  resistance 
offered  the  antagonizing  teeth  through  the  abutments.  In  most 
cases  the  porcelain  can  be  replaced  without  the  removal  of  the 
bridge,  but  the  attachment  is  not  usually  so  reliable  as  in  the 
PiQ  398.  original  piece.     The  following  i& 

the  method  commonly  adopted 
with  incisors  or  cuspids:  The  pins 
of  the  broken  facing  are  cut  off 
and  the  surface  of  the  backing 
trimmed  level.  Mark  the  position 
of  the  pins  of  the  new  facing  on  the 
backing  by  drying  and  flowing  over 
the  surface  a  film  of  beeswax,  then 
with  small  pliers  placing  the  facing 
in  position  and  pressing  the  pins  in 
the  wax;  or  place  a  little  rouge  and 
oil  on  the  end  of  the  pins  and  mark 
the  backing  with  them.  At  the  points  marked  drill  holes  in  the 
backing  to  receive  the  pins  of  the  porcelain  front,  countersinking 
>the  holes  at  the  palatal  side.  After  the  backing  is  drilled  grind 
the  porcelain  to  fit  it  as  perfectly  as  possible,  place  it  in  position 
and  grind  off  the  pins  so  they  slightly  protrude.  If  a  suitable 
long-pin  tooth  is  not  procurable,  the  short  pins  of  an  ordinary 
tooth  can  be  lengthened  by  bending  a  piece  of  platinum  wire  in 
the  form  of  a  semicircle,  and  soldering  its  ends  to  the  ends  of  the 
pins  with  pure  gold.  The  wire  is  then  cut  in  the  center,  and  the 
208 


hi:  I'M  It  OF  Ch'OH'X-  <>i{  bhiixik-work. 


209 


lengthened  pins  trimmed  as  required.     The  pins  are  then  riveted 
on  the  palatal  side  into  the  countersunk  holes  of  the  backing.     The 

riveting   is   best   done 


Fig.  399. 


IS 

with  punch  forceps 
having  a  large  punch, 
the  porcelain  front 
being  protected  by  a 
piece  of  lead  placed 
against  the  labial  as- 
pect (Fig.  398).  The 
heads  of  the  pins  should 
then  be  burnished 
smooth  with  a  revolv- 
ing burnisher.    In  case 


of  the  fracture  of  the  porcelain 
front  of  a  bicuspid  crown  or 
dummy,  a  corresponding  front  is 
selected  with  very  long  pins,  and 
ground  to  fit.  Holes  are  drilled  in 
the  gold,  in  proper  positions,  to  re- 
ceive the  pins  their  full  length. 
The  pins  are  then  roughened  a  little 
with  a  sharp  instrument,  and  pins 
and  front  are  cemented  to  the  gold. 
Should  the  holes  extend  througk 
the  gold  at  the  palatal  side,  the 
cement  and  the  ends  of  the  pins 
should  be  covered  with  gold  foil  or 
amalgam.  If  any  gold  is  present 
to  protect  the  occluding  edge  of 
the  porcelain,  it  should  be  bur- 
nished against  the  surface. 
Dr.  F.  M.  Shriver's  method  of  fastening  the  pins  in  the  ba;cldng 
of  incisors  and  cuspids  is  as  follows:  After  having  fitted  the  porce- 

16 


210  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

lain  facing  and  shortened  the  pins  as  described,  remove  the  porce- 
lain facing  and  with  the  sleeve  drill,  shown  in  place  on  a  tooth 
pin  in  Fig.  399,  countersink  the  end  of  the  pin;  with  the  cone 
bur — for  right  angle — countersink  the  holes  on  the  palatine  sur- 
face of  the  backing.  Prepare  a  small  amount  of  thin  cement  and 
spread  it  over  the  backing,  after  which  place  the  porcelain  facing 
in  position,  and  with  a  pair  of  pliers  firmly  press  the  facing  close 
to  the  backing.  Warm  a  small  piece  of  modelling  compound, 
place  in  the  cup  on  the  riveting  pliers;  then  set  the  riveting  point 
(see  Fig.  399)  in  the  countersunk  end  of  the  pin,  gently  pressing 
the  facing  into  the  modelling  compound;  remove  and  cool  com- 
pound with  ice-water.  Replace,  and  with  a  firm  hand  hold  the 
compound  closely  to  the  facing,  and  with  a  gentle  pressure  on  the 
riveting  point  and  a  slight  lateral  motion  spread  the  pin;  then 
burnish  it  down  with  the  round  point. 

Another  method  to  replace  a  porcelain  front  is  the  following: 
Back  the  porcelain  front  around  the  pins  with  platinum  foil,  bend 
the  pins  down  together  on  the  platinum,  and  hammer  them  flat. 
Invest  and  flow  a  little  gold  plate  over  the  pins  and  platinum,  and 
file  the  metal  down  close  to  the  porcelain.  Drill  a  hole  in  a  strong 
part  of  the  backing  on  the  bridge  at  a  central  point,  square  the 
hole,  and  fit  to  it  a  piece  of  square  platinum  wire.  Attach  the 
end  of  the  wire  to  the  backing  of  the  porcelain  front  with  an  atom 
of  wax  cement,  and  while  warm  insert  the  wire  through  the  hole 
in  the  backing  on  the  bridge,  and  adjust  the  porcelain  front  in  cor- 
rect position.  Chill,  and  remove  front  and  wire.  Invest,  and 
solder  wire  to  backing  on  porcelain  front  with  18-carat  gold  solder, 
and  then  remove  all  metal  from  back  of  porcelain,  except  what  is 
necessary  to  secure  the  end  of  the  wire  to  the  pins.  Countersink 
the  gold  backing  on  the  bridge  sufiicient  to  permit  the  front  to 
come  in  position.  Slit  the  end  of  the  wire,  cement  the  porcelain 
front  in  position  to  the  backing,  and  bend  the  ends  outward  into 
two  slightly  grooved  places  on  the  backing.  Fill  the  slit  in  the 
wire  with  gold  or  amalgam,  and  smooth  the  surface.-^ 

Dr.  R.  W.  Starr's  method  differs  from  the  preceding,  in  that 
he  uses  round  instead  of  square  wire,  cuts  the  pins  of  the  porce- 
lain front  off  short,   making  corresponding  depressions  in  the 

1  Dr.  W.  W.  Williamson's  method. 


REPAIR  OF  C/iOWX-  Oh'  BRIDGE- IVORK. 


211 


backing  on  the  bridge  to  receive  them  and  prevent  rotation,  and 
solders  the  end  of  the  wire  to  retain  the  front  between  the  pins. 
He  then  cuts  a  screw  thread  on  the  wire,  and  secures  it  in  the 
backing  with  a  nut  on  the  palatal  side  screwed  into  a  depression 
reamed  to  receive  it.  Figs.  400,  401,  402,  and  403  illustrate  this 
method. 


Fig.  400. 


Fig.  401. 


Fig.  402.  Fig.  403. 

4  ' 


Dr.  E.  A.  Bryant  describes  a  method^  of  repairing  bridge-work 
by  the  aid  of  a  set  of  tools,  now  made  and  sold  for  the  purpose, 
which  easily  accomplishes  the  results  obtained  in  the  preceding 
example. 

Dr.  Bryant's  method  and  tools  are  briefly  described  as  follows: 

Fig.  404. 


i  ^ 


Each  pin  of  the  selected  tooth-facing  is  to  be  screw-threaded 
with  die  No.  1,  Fig.  404,  first  oiling  the  pin  and  finishing  it  with 
die  i^o.  2.  The  pin-holes  in  the  bridge  backing  are  countersunk 
from  the  rear  with  the  right-angle  engine  reamer  'No.  3  (see  A). 
With  the  nut-driver  ISTo.  4,  one  of  the  gold  nuts  ISTo.  5  is  caught 
on  one  prong  (see  B),  and  started  on  one  of  the  pins  (see  C), 
and  then  the  other  nut  is  likewise  started.  Turning  one  after 
the  other,  the  nuts  are  screwed  tightly  on  (see  D),  and  then  with 
engine  points  the  projecting  pins  and  nuts  are  ground  flush  with 
the  backing. 

1  Dental  Cosmos,  June,  1894,  page  370. 


212  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

Bridge-work  can  be  made  with  replaceable  porcelain  fronts 
which  can  be  easily  substituted  in  case  of  fracture.  A  description 
of  their  application  will  be  found  at  page  187. 

If  the  character  of  the  breakage  is  such  as  will  not  permit  its  re- 
pair in  the  mouth,  the  bridge  must  be  removed  for  the  purpose 
and  then  reinserted.  Under  such  circumstances  the  advantages 
of  bridge-work  in  a  detachable  form  are  most  evident. 

The  results  following  the  repair  of  single  crowns  in  the  mouth 
will  seldom  repay  the  labor  attending  it. 

Removal  of  Cemented  Crowns  and  Bridges. — When  it  becomes 
necessary  to  remove  an  artificial  crown,  whether  inserted  singly 
or  as  a  support  for  a  bridge,  incisors  or  cuspids  are  detached  by 
grinding  the  gold  or  porcelain  away  at  the  palatal  section  over 
the  post,  which  when  exposed  is  severed,  and  the  attachment  of 
the  cement  broken  up.  The  collar  can  also  be  slit  and  bent 
aside  if  foimd  necessary.  If  previous  to  cementation  the  post 
of  the  crown  is  covered  with  a  film  or  sheath  of  gutta-percha, 
as  described  in  process  of  cementation  on  page  137,  the  detach- 

FiG.  405. 


ment  of  the  post  when  the  crown  is  well  heated  is  usually  easily 
effected.  In  an  all-gold  cap-crown  on  a  posterior  tooth  a  hole 
drilled  in  the  grinding-surface  will  give  access  to  the  cement,  a 
sufficient  quantity  of  which  can  then  be  removed  to  loosen  the 
attachment;  or,  the  collar  can  be  divided  and  pried  up  from  the 
root  by  first  making  a  groove  with  a  small  rubber  and  corundum 
disk,  and  then  cutting  the  gold  with  a  sharp  instrument.  A 
crown-cutter,  an  instrument  made  for  the  purpose,  will  facilitate 
this  part  of  the  operation  (see  Fig.  405).  With  care  and  patience 
in  the  operation,  the  crowns  will  not  usually  be  injured  beyond 
repair. 

When  gutta-percha  is  the  cement  that  has  been  used,  a  hot 
instrument  or  crown-setter  (see  Fig.  262)  can  be  placed  against 


RKIWIR  OF  CROWN-  OR  BRIDOE-WOHK.  213 

the  metallic  part  of  the  crown,  or  the  crown  seized  with  the  beaks 
of  heated  forceps,  the  gutta-percha  thereby  softened,  and  the 
crown  removed. 

A  hole  or  slit  in  a  gold  collar  or  crown  is  repaired  easily  by 
first  placing  a  piece  of  soft  wax  in  the  hole  or  slit  on  the  outside 
of  the  gold,  adapting  a  piece  of  platinum  foil  larger  than  the 
aperture  on  the  inside  close  against  the  gold,  and  fixing  it  to  the 
wax.  The  interior  of  the  crown  is  next  filled  with  investing 
material,  and  solder  flowed  over  the  platinum  and  gold  on  the 
outside  of  the  collar  or  crown.  The  crown  should  be  heated 
slowly,  to  allow  the  plaster  to  dry  out  before  the  soldering  is 
begun. 


CHAPTEK   IX. 

THE  HYGIENIC  CONDITION  OF  THE  MOUTH  AS  AFFECTED   BY 

BKIDGE-WOKK. 

The  probable  future  condition  of  a  mouth  in  which  a  piece 
01  bridge-work  is  permanently  fixed  is  a  matter  of  the  deepest 
interest  to  both  patient  and  operator.  There  is  no  valid  reason 
why  an  artificial  structure  in  the  mouth  should  be  more  hurtful 
than  that  which  is  natural,  provided  that  correct  conditions  are 
observed  in  its  construction  and  proper  measures  are  taken  for 
their  maintenance.  The  natural  teeth  demand  care  on  the  part 
of  their  owners,  and  all  forms  of  artificial  dentures  require  at- 
tention to  secure  their  cleanliness  and  thus  preserve  the  health 
of  the  adjacent  tissues.  What  will  result  from  the  wearing  of 
a  permanently  fixed  bridge  is  almost  wholly  dependent,  in  the 
first  place,  on  the  proper  application  of  principles  and  correct 
formation  in  every  detail  of  construction  of  both  crowns  and 
bridge-work;  and  in  the  second  place,  upon  the  maintenance  of 
cleanliness.  E^eglect  of  a  single  requirement  will  so  far  detract 
from  the  usefulness  of  the  work,  and  may  influence  the  final  result 
disastrously. 

Firm,  properly  selected  abutments  will  not  redeem  incorrect 
conception  or  faulty  construction;  neither  will  the  best  construc- 
tion remedy  that  which  is  wrong  in  principle  or  application.  Self- 
cleansing  spaces,  if  properly  formed,  have  exactly  the  contrary 
effect  from  what  is  intended,  by  becoming  receptacles  for  particles 
of  food  debris,  instead  of  preventing  their  accumulation. 

Inaccessible  spaces  or  interstices,  which  are  always  apt  to  cause 
uncleanliness,  should  be  avoided.  Continuity  of  structure  of  the 
several  parts  is  also  essential  to  fully  insure  perfect  hygienic  condi- 
tions. 

The  health  of  a  mouth  containing  a  piece  of  bridge-work  con- 
structed under  these  precautions  can  be  readily  maintained.  For 
this  purpose  a  suitably  formed  brush  and  a  dentifrice  are  neces- 
214 


77//';  lIVdlKNIC  CONDITION  OF  THE  MOUTH.  0\^ 

sary.  Floss  silk  can  be  passed  through  apertures  around  the  necka 
of  crowns,  in  places  out  of  reach  of  the  brush,  and  drawn  along 
the  gum  under  the  bridge  by  the  aid  of  a  slightly  curved  blunt- 
pointed  needle,  to  remove  accumulations  of  debris  otherwise  in- 
accessible. A  solution  of  a  detergent  and  disinfectant  mouth 
lotion  in  water,  injected  with  a  dental  syringe,  can  be  used  ad- 
vantageously to  wash  out  such  places  and  maintain  a  healthy  con- 
dition of  the  gums.  In  addition  to  these  measures,  the  crown  and 
bridge  should  be  thoroughly  cleansed  by  the  dentist  at  regular 
intervals. 

So  cared  for,  a  permanently  fixed  bridge  will  not  militate  against 
the  absolute  wholesomeness  of  the  mouth;  but  it  can  hardly  be 
expected  that  the  insertion  of  bridge-work  will  insure  a  state  of  the 
mouth  which  for  cleanliness  will  be  superior  to  the  presence  of  the 
natural  teeth.  ISTeglect  on  the  part  of  the  patient  to  perform  such 
duties  as  are  necessary  to  preserve  the  natural  teeth  in  a  healthy 
state  will  have  about  the  same  effect  on  an  artificial  denture.  The 
attention  required  to  be  given  to  bridge-work  is  not  greater  than 
is  commensurate  with  the  advantages  which  it  confers  on  the 
wearer. 


CHAPTER    X. 

EEMOVABLE  AND  DETACHABLE   BKIDGE-WOEK. 

The  evident  advantages  of  bridge-work  early  stimulated  the 
inventive  genius  of  dental  mechanists  to  improve  the  methods 
and  forms  of  its  construction  and  to  extend  its  application.  With 
these  objects  in  view,  methods  have  been  introduced  by  whicll 
bridges  are  so  constructed  as  to  be  removable  by  the  patient  or  de- 
tachable by  the  dentist. 

The  construction  of  bridge-work  in  either  of  these  forms  in 
some  cases  overcomes  the  chief  objections  argued  against  the  sys- 
tem. Large  bridges  are  much  more  easily  made  in  a  detachable  or 
removable  form  than  are  the  smaller  pieces,  which  present  some  of 
the  best  features  of  the  permanently  attached  methods. 

Some  forms  of  small  bridges  cannot  be  made  removable.  To 
so  construct  many  others  would  interfere  with  their  practicability. 
Besides,  in  a  large  proportion  of  cases  where  properly  constructed 
bridge-work  is  applied,  the  removable  feature  would  be  of  no 
benefit,  so  far  as  regards  the  health  of  the  abutments  or  of  the  ad- 
joining teeth;  neither  would  it  be  of  any  great  advantage  respect- 
ing cleanliness.  These  reasons,  together  with  the  fact  that  re- 
movable bridge-work  is  most  intricate  and  laborious  in  construc- 
tion, combine  to  restrict  its  use  in  practice.  Much  that  is  here 
stated  concerning  removable  bridge-work  might  be  applied  to  the 
detachable  form.  The  necessity  for  using  the  latter  in  preference 
to  the  former  is  limited  to  a  very  small  sphere,  owing  to  the 
fact  being  demonstrated  that  gutta-percha,  alone  or  combined  with 
oxyphosphate,  can  be  used  practically  as  a  cement  in  most  cases, 
thus  permitting  the  removal  of  a  bridge  without  much  difficulty. 

In  the  construction  of  removable  bridge-work  a  prime  requisite 
is  that  the  posts  and  collars,  or  other  form  of  attachment  used, 
shall  be  so  formed  that  the  piece  shall  move  evenly  on  or  off 
the  supporting  roots  or  crowns  in  adjustment  and  removal.  To 
secure  this,  the  post-cavities  and  the  gold  crowns  should  be  so 
shaped  that  the  lines  of  the  cavities  and  of  the  sides  of  the  gold 
216 


REMOVABLE  INCISOR  OR  CUSPID  CROWN. 


217 


■crowns  shall  be  as  nearly  as  possible  parallel  to  one  another.  To 
facilitate  this,  a  post  of  wood  or  metal  may  be  first  accurately  but 
loosely  inserted  in  any  root-canal  intended  to  receive  a  post,  and 
left  protruding  a  quarter  of  an  inch,  and  an  impression  taken.  On 
the  model  made  from  this  impression  the  post  will  be  found  placed 
as  in  the  mouth.  The  position  and  shape  of  the  natural  teeth  or 
roots  can  be  thus  studied,  and  their  plaster  forms  trimmed  as  a 
guide.  Gutta-percha  or  impression  compound,  fitted  to  the  mode^i 
and  removed  with  the  posts  in  position  in  it,  can  then  be  used  to 
guide  the  operator  and  gauge  the  preparation  of  teeth  or  roots 
in  the  mouth.  Posts,  or  the  tubes  inclosing  them,  should  be 
placed  as  nearly  as  possible  in  the  lines  of  the  root-canals  to  avoid 
weakening  the  side  or  sides  of  the  root. 

When  a  molar  leans  forward,  the  removal  of  a  portion  of  tha 
anterior  approximal  side  usually  restores  its  perpendicularity  suf- 
ficiently, as  does  the  cutting  away  of  the  posterior  side  of  a  bicuspid 
which  inclines  backward. 

The  methods  and  forms  of  attachments  most  commonly  used 
in  the  different  styles  of  removable  bridge  dentures  are  very  simi- 
lar. A  preliminary  description  of  these  and  of  their  constructive 
details  is  therefore  first  in  order. 

REMOVABLE   INCISOR   OR  CUSPID   CROWN. 

A  removable  gold  crown  with  a  porcelain  front  is  frequently 
used  in  connection  with  removable  bridge-work  where  incisors 
or  cuspids  form  abutments.  The  cap  and 
tube  crown  is  the  style  (Fig.  406)  prefer- 
ably applied.  It  consists  of  a  cap  for  the 
€nd  of  the  root  with  a  tube  attached  ex- 
tending up  the  root-canal,  and  on  the  cap 
the  crown  with, a  post  fitted  tightly  to  the 
tube  is  adjusted.  To  the  crown  so  formed 
(Fig.  407)  the  bridge  is  joined  in  the  usual 
manner.  The  end  of  the  post  can  be 
formed  with  a  slit  which  will  permit  this 
portion  to  be  slightly  expanded,  making 
what  is  termed  a  spring-post.  The  con- 
structive details  of  this  crovm  are  as  fol- 
lows :  The  root  is  first  prepared  and  capped 
the  same  as  for  a  collar  crown.     The  collar  can  be  formed  of  gold 


Fig.  406. 


Fig.  407. 


218 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


and  the  cap  section  of  platinum,  ISTo.  32  gauge  (A,  Fig.  408).  A 
substantial  piece  of  gold  and  platinum  wire,  from  IsTo.  16  to  ISTo. 
18  gauge  (the  number  being  regulated  by  the  size  of  the  root),  is 
slit  for  about  one-eighth  of  an  inch  to  form  a  spring-post.  This 
is  easily  done  by  placing  the  wire  in  a  vise  and  steadily  cutting 
it  downward  from  one  end  through  the  center  to  the  required 
depth  with  a  saw-edged  strip  of  very  thin  steel  (Fig.  409).  This 
takes  only  a  few  minutes,  and  is  preferable  to  the  method  some- 
times adopted  of  partially  joining  two  pieces  of  half-round  wire. 
The  wire  is  then  tapped  together  at  the  slit,  burnished  smooth, 
and  rounded  just  at  the  end  (B,  Fig.  408).  The  tube  for  this 
post  is  formed  by  once  encircling  the  post  with  a  piece  of  iridiot 
platinum  plate,  JSTo.  34  gauge,  the  edge  of  which  is  beveled  and 
cut  to  meet  the  plate  even  and  close   (C).     The  post  is  then 


Pig.  408. 


Fig.  409. 


Fig.  410. 


I 


D      W 
B 


withdrawn,  and  the  seam  is  touched  along  its  length  with  the 
smallest  possible  quantity  of  borax.  The  proper  way  to  use  borax 
in  fine  work  is  to  grind  it,  mixed  with  water,  on  a  slab,  to  a  cream- 
like consistence,  and  apply  on  the  point  of  a  camel's-hair  brush. 
A  very  small  piece  of  pure  gold  is  placed  in  the  seam,  and  the  tube 
is  held  in  a  Bunsen  flame.  When  a  sufiicient  degree  of  heat  is 
reached,  the  gold  will  flow  along  the  seam  and  form  a  joint  without 
obstructing  the  inside  passage  for  the  post.  The  post  is  then  in- 
serted, and  the  tube  trimmed  (D),  and  gauged  in  a  gauge-plate. 
With  a  drill  just  the  size  of  the  tube  the  root-canal  is  enlarged  so 
that  the  tube  will  fit  tightly  (Fig.  410).  This  plan  prevents  weak- 
ening of  the  root  by  too  great  enlargement  of  the  canal.  A  hole 
the  size  of  the  tube  is  made  through  the  cap,  and  cap  and  tube  are 
then  adjusted,  waxed  together,  and,  the  post  being  withdrawn, 


REMOVABLE  LWISOIl  OR  (JUSR/D  CROWN. 


219 


they  are  removed,  invested,  with  the  investing  material  inserted  in 
the  tube,  and  soldered.  The  second  or  outer  cap  is  then  con- 
structed for  the  root-cap,  of  a  piece  of  platinum  about  ISTo.  34 
gauge.  It  is  perforated  in  the  center,  and  the  post  fitted  in  proper 
position.  At  the  palatal  and  approximal  sides,  if  desirable,  the 
l^latinum  can  be  slit  and  bent  over  the  edge  of  the  root-cap  to  form, 
an  inner  partial  band  or  flange,  or  a  half  band  can  be  formed  of  a 
piece  of  plate,  the  open  space  at  the  labial  side  being  filled  with 
the  porcelain  tooth.  The  outer  cap  and  the  post,  having  been 
cemented  with  wax,  are  removed  and  soldered  together.  As  the 
point  of  the  post  may  have  to  be  filed,  it  is  well  to  place  it  so  that 
the  line  of  the  slit  shall  cross  the  tooth  from  mesial  to  distal  side. 
On  this  outer  cap  the  porcelain  front  is  fitted  and  soldered.  The 
end  of  the  tube  is  closed  with  a  little  gutta-percha,  and  the  root- 
cap  cemented  on  the  root  with  oxyphosphate  and  the  crown  placed 
on  it,  wliich  helps  to  bring  the  root-cap  to  its  place  and  insures 
the  intended  position  of  the  crown.  When  necessary,  the  split 
post  can  be  tightened  in  the  tube  by  slightly  springing  it  open. 
Fig.  407  represents  the  finished  crown.  The  incisive  edge  of  the 
porcelain  does  not  necessarily  require  to  be  protected  with  metal 
as  in  fixed  bridge-work. 

A  square  tapering  post,  either  solid  or  split  in  some  cases,  is 
preferred  to  the  form  above  descrilied,  especially  in  a  root  of  a 
cuspid.  When  a  split  post  is  used,  the 
points  should  be  soldered  together.  The 
lower  section  of  the  post  can  then  be  alone 
expanded  and  tightened  in  the  tube  (Tig. 
411).  To  receive  the  tube  and  post,  the 
canal  should  be  carefully  deeply  opened 
and  then  shaped  mth  a  reamer,  such  as  is 
illustrated  at  Tig.  72. 

Fig.  412  illustrates  a  removable  cuspid 

crown  which  can  be  used  in  removable 

bridge-work.     It  is  constructed  as  follows: 

The  end  of  the  root  is  first  capped,  and  a 

post    attached    fitting   the    root-canal.     A 

j^orcelain  cross-pin  tooth,  the  pins  of  which  are  set  w^ell 

apart,  is  then  ground  and  adjusted  in  position,  cemented 

with  wax  to  the  cap,  and  both  removed.     Enough  plas- 


FiG.  411. 


Fig.  412. 


220  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

ter  to  form  a  matrix  is  placed  on  the  labial  aspect  of  the  porcelain 
and  collar  to  hold  them  in  relative  position  when  the  wax  is  re- 
moved. A  flat  post  is  then  formed  on  the  root-cap,  extending  from 
the  palatal  edge  forward  between  the  pins  of  the  tooth,  the  porce- 
lain of  which,  between  the  pins,  should  be  slightly  cut  out  to 
receive  it.  To  this  is  soldered  the  piece  A,  which  is  to  act  as  a 
spring.  The  post  is  formed  of  gold  plate  ISTo.  18  gauge,  and 
the  spring  of  clasp  or  spring  gold  J^o.  26.  The  post  is  soldered 
to  the  cap  from  the  opposite  side  to  the  spring  by  investing  with- 
out the  tooth.  The  tooth  is  then  lined  with  very  thin  platinum, 
and  with  the  aid  of  the  matrix  is  adjusted  in  position  on  the 
cap,  and  a  thin  piece  of  platinum  plate  is  slit  at  the  edges  and 
adapted  over  the  post,  cap,  and  edge  of  the  collar,  with  its  inner 
edge  meeting  the  backing  of  the  tooth.  The  platinum  plate  is 
then  cemented  with  wax  to  the  backing  on  the  tooth,  removed 
with  it  from  the  cap  and  post,  and  invested,  the  slot  for  the  post 
being  carefully  filled  with  the  investing  material.  Twenty-carat 
gold  solder  is  then  flowed  over  the  plate  and  backing  so  as  to  con- 
solidate the  parts  in  one  piece. 

This  crown  when  finished  will  fit  on  to  the  cap  and  post,  the 
spring  of  which  can  be  bent  to  securely  retain  it.  The  line  of 
the  post  on  the  cap  as  it  fits  in  the  slot  in  the  crown  should  be 
such  as  will  favor  the  insertion  and  removal  of  the  bridge. 

In  the  form  shown  in  Fig.  413,  which  is  a  sectional  view,  a 
square  or  round  iridio-platinum-  wire  is  used  as  a  post 
^r^  on  the  cap  instead  of  the  form  above  described. 

p  \  The  post  having  been  soldered  to  the  cap,  a  thin 

M|"V  j       piece  of  platinum  is  first  perforated  and  fitted  over 

B  the  top  of  the  cap,  next  a  tube  of  platinum  over  the 

^,__-_^  post  and  between  the  pins  of  the  porcelain.  The 
MjT]\  porcelain  front  is  then  lined  with  platinum  foil,  and 
\  i_  /  /  cemented  with  wax  to  the  tube  and  the  platinum  at 
the  base,  and  removed  and  soldered  together.  AVhere 
one  end  of  a  bridge  is  securely  attached  to  a  first  molar  having  a 
long  crown,  the  form  of  crown  here  described  is  ample  support  for 
the  other  end  on  a  cuspid. 


JIKMOVABLK  BICUSPID  AND  MOLAR  ATTACHMENTS.       221 


REMOVABLE   BICUSPID  AND   MOLAR   ATTACHMENTS. 

Biciisi)ids  and  molars,  especially  the  latter,  in  all  cases  where 
possible,  are  the  teeth  selected  and  most  depended  on  to  support 
all  forms  of  removable  bridge-work. 

Removable  Partial  Cap  and  Collar. — This  is  a  form  of  attach- 
ment made  to  fit  over  a  natural  tooth,  or  more  frequently  a  gold 
crown. 

The  sides  of  the  natural  tooth  have  to  be  first  trimmed  as  nearly 
as  possible  straight  or  parallel  to  the  sides  of  any  other  supporting 
crown  or  line  of  attachment.  If  the  tooth  is  to  be  first  capped,  a 
straight-sided  gold  crown  is  made  and  fitted.  A  fusible-metai  die 
of  the  gold  crown  is  then  made;  or,  better  still,  the  gold  crown  is 
removed,  a  strip  of  damp  paper  wound  around  it,  and  fusible  metal 
melted  and  poured  in  crown  and  paper  tube.     This  forms  a  die  of 


Fig.  414. 


Fig.  415. 


Fig.  416. 


the  crown,  with  a  shank  as  seen  in  Kg.  414.  When  the  natural 
tooth  is  not  crowned  with  gold,  a  die  of  the  tooth  is  made  in  a  man- 
ner similar  to  that  described  on  page  96,  and  in  chapter  on  "Molds 
and  Dies."  The  crown  is  then  encircled  with  a  strip  of  pure  gold 
about  JSTo.  30  gauge,  one  part  of  which  will  extend  above  the  rest 
in  the  form  shown  in  Fig.  415. 

The  sections  of  the  gold  at  A,  A  are  to  reach  from  the  edge 
of  the  neck  of  the  crown  to  or  slightly  above  the  occluding  sur- 
face. The  gold  is  fitted  evenly,  but  not  tightly,  around  the  crown, 
the  ends  being  placed  at  the  side  opposite  to  that  where  the  collar 
will  be  joined  to  the  bridge  if  the  space  permits.  The  collar  is 
then  removed  and  the  ends  soldered  together  (Fig.  416).  The 
collar  is  readjusted  on  the  crown,  and  the  part  at  B,  Figs.  416  and 
418,  bent  down  over  the  occluding  surface,  so  that  it  nearly  meets 
the  collar  section  A.  On  the  outside  of  the  collar  a  slightly  nar- 
rower strip  of  gold  clasp  plate,  ISTo.  30  (Fig.  417),  is  next  adjusted 


222 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


ill  the  position  shown  at  the  lines  C,  Fig,  41Y,  then  removed  and 
the  seam,  which  had  best  be  located  at  the  point  C,  Figs.  417  and 
418,  soldered  together.  It  is  readjusted  on  the  gold  collar,  re- 
moved with  it,  and  soldered  to  it.  The  collar  can  be  invested  for 
this  purpose,  but  the  work  is  more  easily  done  by  holding  the  col- 
lar in  a  Bunsen  flame  and  placing  small  pieces  of  solder  in  posi- 
tion in  the  seam.  Only  enough  solder  should  be  used  to  unite 
the  parts,  any  surplus  being  carefully  avoided.  Painting  the 
inner  surface  of  the  collar  with  whiting  will  prevent  the  solder 
flowing  there. 

The  collar  section  of  the  removable  cap  is  then  trimmed  smooth. 
The  cap  section  at  B  can  be  adjusted  and  soldered  to  the  collar 
now,  or  preferably  after  the  cap  has  been  united  to  the  bridge, 
and  its  relative  position  on  the  gold  crown  accurately  determined. 
Fig.  419  shows  the  gold  crown  and  the  finished  removable  par- 
tial gold  cap  over  it. 


Fig.  417. 


Fig.  418. 


Fig.  419. 


Fig.  420. 


The  gold  crown  is  freed  from  the  fusible  metal  by  dropping 
it  with  the  die  into  a  ladle  containing  a  quantity  of  melted  fusible 
metal.  The  portion  within  the  crown  will  melt  in  with  that  in 
the  ladle  and  leave  the  crown,  which  should  then  be  removed 
and  immersed  in  nitric  acid  to  remove  any  traces  of  the  fusible 
metal  still  adhering  to  the  gold. 

Flanged  Collar  Attachment. — Fig.  420  shows  another  form  of 
removable  partial  cap.  In  this  the  entire  edge  of  the  collar  is 
bent  over  on  the  occluding  surface  of  the  crown,  and  thereby 
supported  in  position.  In  the  construction  the  edge  of  the  pure 
gold  collar  should  be  shaped  to  form  the  flange. 

This  form  of  collar  may  also  be  made  entirely  of  clasp  gold, 
No.  28  gauge  for  molars,  and  of  I^o.  29  to  30  gauge  for  bicuspids. 
The  process  is:  An  accurately  fitting  collar  is  first  made.     The 


REMOVABLE  BICUSPID  AXIJ  MOLAJi  ATTACIIMKXTS.        223 

collar  is  then,  by  tapping  with  a  small  horn  or  copper  hammer, 
aided  by  frequent  annealings,  shaped  on  the  gold  crown  or  die 
of  the  tooth.  The  flange  section  can  be  slightly  thinned  with 
a  small  corundum- wheel,  and  then  or  subsequently  brought  to 
position  over  the  gold  crown,  or  the  tooth,  and  stiffened  with 
solder.  When  the  collar  is  shaped  over  the  gold  crown,  the 
crown  should  be  first  filled  with  fusible  metal  as  previously  de- 
scribed. 

Spur  Collar  Support. — Fig.  421  illustrates  a  form  in  which  a 
straight-sided  removable  collar  is  maintained  in  position  by  a 
lug  or  spur  on  the  side  of  a  gold  crown. 


Fig.  421.  Fig.  422. 


Fig.  424. 


Removable  Partial  Cap  and  Clasp  Attachment. — In  this  form  a 
partial  cap  in  combination  with  an  elastic  gold  clasp,  encircling 
only  a  portion  of  the  crown,  is  used  instead  of  a  collar.  Its  ap- 
plication is  principally  confined  to  a  cuspid  or  bicuspid  tooth  or  an 
artificial  crown. 

The  attachment  is  best  constructed  on  a  metallic  die,  either 
of  the  natural  tooth  or  of  the  artificial  crown  mounted  on  a  model. 
In  the  case  of  a  cuspid  a  piece  of  pure  gold,  ITo.  31  gauge,  is 
adapted  to  the  palatal  surface  and  partly  over  on  the  approximal 
side,  in  the  form  shown  at  A,  Fig.  422.  In  some  cases  it  may  be 
extended  to  the  incisive  edge.  A  gold  clasp  of  at  least  'No.  24 
gauge  is  fitted  over  the  gold  partial  cap  in  the  position  shown  in 
Fig.  423,  the  cap  being  beveled  to  an  imperceptible  edge  on  the 
sides  at  the  points  where  the  clasp  passes  forward,  to  assure  perfect 
adaptation.  Cap  and  clasp  are  next  cemented  with  wax,  then  re- 
moved and  joined  at  the  approximal  sides  with  a  very  small  quan- 
tity of  solder.  The  attachment  is  then  ready  to  be  connected  to 
the  bridge  denture,  which  should  be  done  by  soldering  the  clasp 
portion  only  at  the  point  B,  Fig.  423.     This  method  allows  the 


224  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

soft  gold  of  the  cap  portion  to  be  again  adapted  to  suit  any  posi- 
tion the  clasp  may  assume  in  the  final  adjustment  of  the  denture 
in  the  mouth.  The  bridge  and  clasp  should  then  be  invested 
again,  and  solder  flowed  over  and  between  the  cap  and  clasp. 

A  Bicuspid  or  Molar  Partial  Cap  and  Clasp  Attachment. — 
Fig.  424  illustrates  the  form  the  attachment  just  described  usually 
assumes  in  cases  of  bicuspids  and  molars.  The  dotted  line  marks 
the  boundary  of  the  partial  pure  gold  cap.  The  construction  fol- 
lows similar  lines  to  those  laid  down  in  the  case  of  a  cuspid.  If 
preferable,  the  cap  section  can  be  burnished  down  against  the 
crown;  and  if  necessary,  it  can  be  slit,  and  solder  can  be  flowed 
over  it  at  the  final  adjustment  of  the  bridge.  This  form  of  at- 
tachment is  especially  useful  in  cases  where  a  natural  tooth  tips 
out  of  line  so  as  to  render  it  difficult  to  entirely  encircle  it  with  a 
continuous  band. 

Pure  gold  has  been  given  the  preference  to  thin  platinum  in 
the  construction  of  these  partial  caps,  for  the  reason  that  the 
form  and  the  position  of  the  former  are  less  liable  to  be  altered 
in  soldering,  an  advantage  which  is  relatively  more  important  than 
the  non-fusible  quality  of  the  platinum. 

The  forms  of  attachments  described  for  removable  bridge- 
work  are  those  most  generally  applied  in  practice.  The  methods 
for  their  construction,  which  as  given  are  the  results  of  practical 
experience,  may  in  some  respects  differ  from  those  followed  by 
others.  In  application,  as  will  be  shown,  they  enable  the  operator 
to  avoid  difficulties  often  encountered  in  obtaining  a  proper  adjust- 
ment of  removable  bridges  on  the  abutments  and  alveolar  border. 
Special  forms  of  attachments  not  in  general  use  will  be  described 
in  the  succeeding  chapters,  in  their  application  to  practical  cases. 
Their  use  in  combination  with  the  forms  already  explained  may 
at  times  prove  advantageous. 

Connecting  Bars. — Connections  between  the  different  sections 
of  a  removable  bridge  are  formed  in  the  following  manner;  An 
impression  of  the  case  or  of  the  part  to  be  spanned  is  taken  in 
plaster,  and  a  cast  made  by  pouring  into  it  fusible  metal  which 
melts  at  a  point  less  than  or  not  over  two  hundred  degrees  (see 
chapter  on  "Molds  and  Dies").  The  cast  must  correctly  repre- 
sent the  lingual  or  palatal  surfaces  of  the  teeth.  Upon  this  cast 
a  strip  of  pure  gold,  iSTo.  30  gauge,  about  one-quarter  of  an  inch 


REMOVABLE  BfC'I'SI'/D  AND  MOLAR  ATTACHMENTS.        225 

in  width  and  of  the  proper  length  for  the  required  connecting 
bar,  is  burnished  over  the  palatal  or  lingual  surface  of  the  teeth 
intervening  between  sections  of  the  bridge  or  attachment  to  be 
connected.  Wax  is  placed  on  the  surface  of  the  gold,  and  the 
gold  is  removed  and  invested.  The  wax  is  next  removed,  and 
a  piece,  or  pieces,  of  gold  clasp  plate,  a  trifle  narrower  than  the 
strip  of  pure  gold,  is  bent  and  shaped  to  fit  over  its  surface. 
Twentj-carat  solder  is  then  flowed  over  the  gold  in  quantity  suf- 
ficient to  join  the  parts,  level  the  surface,  and  make  a  rigid  bar 
capable  of  resisting  such  force  in  use  as  would  tend  to  destroy  its 
shape  in  the  slightest  degree.  When  the  bar  is  formed  on  the 
metallic  cast  it  can  be  transferred  to  the  plaster  model,  and  then, 
or  in  the  subsequent  construction  of  the  work,  connected  to  the 
attachments;  or  the  bar  can  be  adjusted  in  the  mouth,  cemented 

Fia.  425. 


with  wax  or  ligatured  on  the  teeth,  the  attachments  placed  in  posi- 
tion, and  the  bar  and  attachments  removed  in  their  relative  posi- 
tions in  a  plaster  impression.  On  the  model  made  from  this 
impression  they  will  be  found  the  same  as  in  the  mouth.  The 
construction  of  the  bridge  can  then  be  continued.  Fig.  425  rep- 
resents a  bar  of  this  character  to  span  the  lower  front  teeth  and 
connect  attachments  on  the  cuspid  and  bicuspid. 

For  the  Upper  Front  Teeth. — Where  a  bar  narrower  than  the 
one  described  is  required,  the  strip  of  pure  gold  should  be  cut  pro- 
portionately, and  pieces  of  half-round  iridio-platinum  or  gold  clasp 
wire  used  to  form  and  stiffen  the  bar,  instead  of  gold  clasp  plate. 
Iridio-platinum  wire  may  be  used  without  the  pure  gold  base,  but 
in  such  a  case  the  sections  of  the  wire  are  best  soldered  with  either 
pure  gold  or  22-carat  plate.     Methods  for  connecting  sections  of 

16 


226 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


a  bridge  are  illustrated  in  Figs.  303,  351,  353,  430,  434,  447,  482, 
590,  and  594. 

Construction  of  Benwvahle  Bridge-Worh. — In  removable,  as 
well  as  other  styles  of  bridge-work,  the  method  of  procedure  i& 
governed  entirely  by  the  conditions  presented  in  each  case. 
Therefore  directions  given  regarding  bridge-work  embracing  cer- 
tain teeth  and  attachments  in  one  instance  may  vary  considerably 
from  what  is  required  for  the  same  tooth  in  another;  consequently 
the  process  of  construction  can  only  be  outlined  in  somewhat  gen- 
eral terms. 

Fig.  426. 


A  case  frequently  presented,  involving  the  loss  of  a  portion  of 
the  lower  teeth,  as  shown  in  Fig.  426,  will  be  taken  to  illustrate  the 
method  generally  adopted  for  the  construction  of  removable 
bridge-work. 

The  molar  is  shaped  to  receive  a  gold  crown.  The  anterior 
approximal  side  is  trimmed  parallel  with  the  line  of  the  posterior 
side  of  the  cuspid.  Removing  a  little  of  the  enamel  on  the  distal 
side  of  the  cuspid  will  assist  the  operation  and  straighten  that 
part  of  the  tooth.  A  straight-sided  gold  crown  is  made  for  the 
molar,  A  bite  is  first  taken  in  wax  for  articulating  model  and 
then  a  plaster  impression,  which  will  remove  the  gold  molar  crown 
in  position,  and  a  cast  is  made  as  follows :  The  form  of  the  cuspid 
is  first  filled  with  fusible  metal,  and  the  remainder  of  the  im- 
pression with  pure  plaster,  as  described  in  chapter  on  "Molds  and 
Dies.*' 

A  die  is  then  made  of  the  gold  crown  and  a  removable  cap  for 
the  gold  crown  on  this  die,  and  a  gold  partial  cap  and  clasp  attach- 
ment are  made  on  the  metallic  form  of  the  cuspid.  Dummies 
are  then  fitted  and  soldered  together,  placed  in  position,  and  joined 


REMOVABLE  BKJUSI'ID  AND  MOLAR  ATTACHMENTS.        227 

to  the  attachments  with  wax  cement.  The  bridge  is  then  removed 
from  the  model,  invested,  and  soldered  together.  In  the  removal 
of  this  style  of  work  from  the  mouth  or  from  a  model,  should  the 
wax  not  hold  the  parts  reliably  together,  plates  should  be  placed 
over  them,  so  that  when  removed  they  can  be  accurately  readjusted 
in  the  plaster.  Connection  with  the  attachment  is  only  to  be  made 
at  the  collar  section.  The  gold  crown  and  fusible  metal  are  then 
separated  from  the  model  and  the  fusible  metal  removed  from  the 
crown  in  the  manner  described  on  page  222. 

The  molar  crown  and  the  bridge  are  then  fitted  to  the  mouth. 
The  crown  is  next  cemented  on  the  molar  and  the  bridge  im- 
mediately adjusted  over  it,  pressed  into  position,  and  allowed  to 
remain  until  the  cement  has  set.  The  partial  cap  section  of  the 
attachments  is  burnished  down  on  the  bicuspid  and  the  gold  crown 
on  the  molar,  while  the  bridge  is  kept  firmly  pressed  against  the 
gums.  The  bridge  is  then  removed,  invested,  and  the  partial  cap 
sections  made  rigid  by  flowing  gold  solder  over  them.  The  final 
trimming,  finishing,  and  polishing  of  the  bridge  are  then  per- 
formed, and  it  is  ready  for  insertion. 

The  procedure  in  the  case  described  can  be  varied  by  making 
the  entire  model  of  fusible  metal,  or  by  placing  a  little  wax  in 
the  interior  of  the  grinding-surface  of  the  gold  crown,  making 
a  plaster  model,  removing  the  gold  crown  and  filling  it  with  fusible 
metal,  making  the  attachment  and  replacing  the  gold  crown  on  the 
model.  The  cuspid  attachment  can  be  formed  on  a  fusible  metal 
cast  of  the  tooth. 

The  methods  of  construction  as  above  given  may  be  still  further 
varied  by  first  forming  the  gold  crown  and  attachments  to  it  and 
the  cuspid,  fitting  them  in  position  in  the  mouth,  taking  a  plaster 
impression  which  will  remove  them  in  position,  and  then  making 
a  model  of  plaster  and  calcined  marble-dust.  On  this  the  dum- 
mies can  be  fitted  and  soldered  to  the  attachments.  The  gold 
crown  is  to  be  removed  from  the  model  after  the  position  of  the 
attachment  on  it  is  secured  by  the  investing  material,  and  the 
cavity  in  the  investment  is  then  to  be  filled  with  more  investment 
material. 

Removable  bridge-work  is  best  constructed  with  the  bases  of 
the  dummy  teeth  pressing  firmly  on  the  tissue  of  the  gum.  If 
the  collar  of  the  molar  attachment  should  prove  difficult  to  remove 


228 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


when  first  inserted,  it  should  be  slit  at  the  posterior  section,  slightly 
expanded,  and  reunited  with  solder,  when  the  cap  sections  of  the 
attachments  are  stiffened  in  the  final  process  of  soldering.  A 
small  piece  of  gold  plate  can  be  inserted  in  the  aperture  of  the 
collar  to  aid  the  gold  to  unite  the  ends. 

In  Fig.  427  are  illustrated  the  two  forms  of  removable  bridge- 
work  that  could  be  constructed  for  the  same  case.  In  the  one 
a  clasp  attachment  is  placed  on  the  natural  cuspid,  in  the  other 
the  natural  crown  is  excised  and  a  removable  cuspid  crown  con- 

FiG.  427. 


structed.  In  the  construction  of  either  style,  a  gold  crown  is 
made  for  the  molar,  with  a  removable  gold  partial  cap  and  collar 
attachment.  A  removable  partial  cap  and  clasp  attachment  is 
made  for  the  cuspid,  or,  if  the  natural  crown  is  excised,  a  re- 
movable cuspid  crown,  and  the  cap  and  tube  section  cemented 
in  position  on  the  root.  The  crown  or  crowns  and  attachments 
are  adjusted  in  position  in  the  mouth.  If  the  cuspid  attachment 
is  used,  and  it  seems  liable  to  become  misplaced,  it  can  be  liga- 
tured to  the  natural  crown.  An  impression  and  bite  are  then 
taken  in  plaster,  and  when  removed  from  the  mouth  the  croAvns 
and  attachments  are  to  be  replaced  in  position  in  the  impression, 
and  a  model  of  plaster  and  calcined  marble-dust  made,  and  also 
an  articulating  model  in  plaster.  The  lateral  and  bicuspid  and 
molar  dummy  teeth  are  next  fitted  in  proper  position  on  the 
model.  A  piece  of  pure  gold  is  adapted  against  the  lateral,  and 
burnished  over  the  palato-approximal  side  of  the  central  to  form 
the  flange.     The  case  is  then  invested,  the  gold  crown  slipped 


REMOVABLE  BlfUSPW  AND  MOLAR  ATTACHMENTS.        229 

out  of  the  attachment,  the  place  it  occupied  is  filled  with  ad- 
ditional investing  material,  and  the  parts  are  all  soldered  to- 
gether. The  construction  can  he  varied  by  first  making  the 
bridge  from  the  molar  to  the  cuspid,  and  then  adding  the  lateral 
and  flange.  When  finished,  a  suitable  quantity  of  cement  is 
placed  in  the  gold  crown,  the  crown  is  fitted  on  the  molar,  the 
bridge  adjusted  in  position,  and  the  teeth  occluded  and  so  allowed 
to  remain  until  the  cement  sets. 

The  denture  illustrated  in  Fig.  428,  a  case  of  Dr.  A.  S.  Rich- 
mond's, was  made  to  restore  a  loss  of  teeth  which  is  frequently 

Fig.  428. 


met  with,  but  one  not  suitable  for  the  insertion  of  cemented 
bridge-work.  The  application  of  a  removable  denture  combin- 
ing bridge-  and  plate-work  is  a  method  possessing  some  advantages 
over  those  ordinarily  practiced.  In  brief,  the  constructive  de- 
tails are:  A  connecting  bar  is  formed  as  described  on  page  224. 
In  the  case  in  hand,  when  the  pure  gold  to  form  the  connecting 
bar  is  adapted  to  the  cast,  it  is  extended  around  and  over  the  cuspid 
and  bicuspid.  Gold  clasps  are  then  adapted  over  the  pure  gold 
on  these  teeth,  and  attached  with  solder.  The  bar  and  clasp  at- 
tachments are  inserted  in  the  mouth,  and  an  impression  taken  in 
plaster.  Two  pieces  of  sheet  lead  about  No.  26  gauge  are  placed 
on  the  surface  of  the  impression  where  the  saddles  are  to  rest, 
for  the  purpose  of  causing  an  equal  displacement  on  the  plaster 
model  and  thus  securing  an  even  pressure  for  the  saddles  on  the 
alveolar  ridge.  (See  page  173.)  A  model  is  next  made  with 
the  attachments  and  bar  on  it  in  position.  Metal  casts  are  also 
made  of  the  parts  at  A,  A,  Fig.  429,  and  two  gold  plates  struck  up. 
The  teeth  are  then  arranged  in  position,  the  bicuspids  resting  on 
the  gums  and  the  molars  on  the  two  plates  or  saddles,  and  thei 
denture  completed  as  shown  in  the  illustration. 


230 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Removable  bridge-work  offers  peculiar  advantages  for  artificial 
replacement  of  lower  incisors  in  cases  similar  to  that  illustrated  in 
Fig.  430.  A  portion  of  the  contour  of  the  approximal  sides  of  tbe 
right  cuspid  is  removed.  Shell  caps  for  the  right  and  left  cuspids 
are  then  formed  of  crown  gold,  reaching  nearly  to  the  margin 


Fig.  429. 


of  the  gum.  The  caps  are  encircled  with  a  narrow  strip  of  stiff 
gold  plate  or  clasp  metal,  about  JSTo.  35  gauge,  which  is  soldered 
to  the  caps  as  described  on  page  224  in  the  construction  of  molar 

Fig.  430. 


partial  caps,  or  are  stiffened  by  flowing  a  film  of  coin  gold  or  solder 
over  their  surface.  The  caps  are  next  adjusted  in  the  mouth,  and 
an  impression  and  bite  taken  in  plaster  and  the  caps  removed  in  it. 
A  model  of  half  each  plaster  and  marble-dust  and  an  articula- 
tion in  plaster  are  then  made.  Porcelain  incisor  teeth  with 
straight  pins  are  fitted  in  position,  backed,  and  a  broad  bar  ex- 
tending from  the  lingual-approximal  side  of  the  gold  cap  on  the 


REMOVABLE  BWUSPID  AND  MOLAR  ATTACHMENTS.        231 

left  cuspid  around  to  the  mesial  side  of  the  lateral  is  formed  of  a 
strip  of  pure  gold,  adapted  to  the  parts,  overlaid,  and  soldered 
to  a  slightlj  narrower  strip  of  gold  clasp  plate.  The  different 
portions  are  then  cemented  together  with  wax,  invested  on  the 
model,  and  properly  united  with  solder.  When  finished  and 
inserted  in  the  mouth,  it  constitutes  a  denture  that  can  be  worn 
without  inconvenience  by  the  patient,  and  removed  daily  and 
cleansed,  which  last  especially  is  a  great  advantage,  as  in  a  case 
like  this  the  teeth  replaced  have  usually  been  lost  by  pyorrhea 
alveolaris  and  those  remaining  are  affected  by  the  same  trouble. 

Fig.  431. 


The  natural  teeth,  if  loose,  are  in  a  measure  steadied  and  sup- 
ported by  the  appliance.  In  some  cases,  especially  if  the  teeth 
tip,  one  or  both  of  the  attachments  on  the  cuspids  can  be  made 
of  thick  clasp  metal  in  the  form  of  a  clasp  attachment,  as  de- 
scribed on  page  224. 

In  the  case  represented  in  Tig.  431,  gold  crowns  with  remov- 
able partial  cap  and  collar  attachments  are  made  for  the  molar 
and  bicuspid,  and  removable  crowns  with  flanges  of  the  metal  on 
the  palatal  sides  for  the  centrals  and  cuspid.  The  right  central 
is  capped  and  the  crown  fitted  over  it  without  a  post,  as  the 
posts  in  the  other  two  crowns  afford  ample  security. 

After  the  crowns  are  made,  the  root-caps  are  cemented  on  each 
root.  The  central  crowns  are  cemented  together  with  wax,  ad- 
justed in  position,  covered  with  a  small  quantity  of  investing  ma- 


232 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


terial,  removed,  more  investing  material  added,  and  the  crovi^ns 
soldered  together. 

The  centrals  and  the  cuspid  are  then  adjusted  in  the  mouth, 
a  lateral  is  backed,  fitted,  and  waxed  between  them  in  position, 


Fig.  432. 


the  whole  removed  in  investing  material,  and  the  process  of  in- 
\'esting  and  soldering  proceeded  with  to  join  the  parts  as  before 
desc^ribed.     This  bridge  of  four  teeth  is  fitted  to  the  mouth,  and 


Fig.  433. 


the  points  of  the  posts  trimmed  on  the  side  and  in  the  direction 
which  will  best  favor  their  entrance  into  the  tubes  in  each  root, 
so  that  the  bridge  will  readily  slip  into  position.  The  dummy 
bicuspids  and  molar  on  the  right  side  between  the  cuspid  and 
molar  are  then  added  by  first  taking  an  impression  and  bite  of  that 


REMOVABLE  BICUSPID  AND  MOLAR  ATTACHMENTS.       233 

section,  and  then  proceeding  with  the  construction  as  described  in 
previous  cases.  The  section  of  the  bridge  with  the  extension  on 
the  left  side  is  next  added  in  a  similar  manner  by  taking  an  im- 
pression of  the  part  while  the  portion  of  the  bridge  already  con- 
structed is  in  position,  removing  bridge  and  impression  together  as 
described  on  page  228,  and  making  a  model.  A  piece  of  pure 
gold  is  shaped  to  the  model  by  alternately  burnishing  and  an- 
nealing, to  form  a  base  for  the  molar.  The  one  molar  will  exert 
as  much  leverage  on  the  abutment  of  the  bridge  in  mastication 
as  can  f^afely  be  borne. 

Fig.  432  shows  the  bridge  completed,  and  Fig.  433  the  piece 
in  position. 


CIIAPTEK    XI. 

KEMOVABLE   PLATE    BEIDGE-WORK. 

I]sr  this  style  of  work  a  plate  is  used  to  span  the  space  and  sup- 
port the  artificial  teeth  between  the  abutments.  Attachments 
similar  to  those  used  in  connection  with  removable  bridge-work 
are  also  applicable  to  removable  plate  bridges.  Removable  plate 
bridge-work  is  really  plate-work  secured  in  position  by  removable 
bridge-work  attachments,  and  is  intended  to  combine  in  a  denture 
the  advantages  of  both  systems.  In  the  construction  of  removable 
plate  bridge-work,  removable  crowns,  caps,  or  attachments  are 
made  for  the  supporting  teeth  in  the  same  manner  as  for  remov- 
able bridge-work,  though  clasp  attachments  may  be  somewhat 
more  freely  used. 

An  impression  of  the  part  is  taken,  from  which  a  plaster  model 
is  made.  On  the  model  an  outline  of  the  size  of  the  required 
plate  is  marked  and  the  edge  of  the  space  scraped  sufficiently  to  in- 
sure a  slight  pressure  for  its  margins.  A  metallic  die  and  counter- 
die  are  cast,  and  a  gold  plate  of  the  proper  size  swaged.  The  at- 
tachments are  adjusted  in  the  mouth  and  the  plate  fitted  in  posi- 
tion between  the  attachments,  and  then  the  plate  is  removed.  A 
plaster  impression  is  next  taken,  and  the  attachments  removed  in 
position  in  the  impression.  The  gold  plate  is  turned  upside  down 
and  placed  on  the  surface  of  the  plaster  impression  between  the 
attachments,  an  atom  of  sticky  wax  being  applied  at  a  point  or 
two  if  necessary  to  retain  it  in  position.  A  model  is  run  in  the 
impression,  composed  of  marble-dust,  sand,  or  finely  shredded  as- 
bestos, and  plaster,  of  each  one  part.  When  the  plaster  impression 
is  removed  from  the  model,  the  plate  will  be  found  imbedded  in 
place  between  the  attachments.  The  attachments  are  then  se- 
curely soldered  to  the  plate.  If  necessary,  before  soldering,  a 
little  more  investing  material  may  be  added  to  protect  the  attach- 
ments. A  plate  made  after  this  method,  when  fitted  "with  the  at- 
tachments in  the  mouth,  will  press  on  the  membranes  of  the 
234 


REMOVABLE  I'LATE  JiJUD<JE-\V<JliE. 


235 


alveolar  ridge  sufficient  to  displace  them  to  fully  the  thickness  of 
the  plate. 

Another  method  to  obtain  a  similar  result  is:  Strike  up  on  the 
die  a  plate  of  sheet  lead  from  jSTo.  22  to  32  gauge,  according  to  the 
hardness  of  the  tissues  and  the  pressure  desired.  Fit  and  place 
the  lead  plate  in  the  plaster  impression,  and  after  the  model  is 
made,  remove  the  lead  and  substitute  the  gold  plate  for  it  on  the 
model,  and  then  solder  the  attachments.  By  this  latter  method 
you  can  regulate  the  pressure  of  the  gold  plate  equally  over  the 
membranes  to  any  desired  degree. 

Fig.  434. 


Pressure  of  the  plate  on  the  tissues  in  small  cases  of  plate  bridge- 
work  can  be  obtained,  but  less  reliably,  in  the  following  manner: 
Cement  the  attachments  to  the  plate  with  sticky  wax,  adjust  in 
the  mouth,  press  on  the  plate,  chill  the  wax  with  ice-water,  remove, 
invest,  and  solder  the  attachments  to  the  plate.  The  plate  and  at- 
tachments are  next  fitted  in  the  mouth,  an  articulating  impression 
taken,  and  articulating  models  made.  The  case  is  then  finished 
with  plain  or  gum  teeth,  attached  with  vulcanite  or  gold  as  circum- 
stances may  suggest.  Should  a  clasp  attachment  cause  decay  or 
abrasion  of  a  tooth,  the  part  can  be  excavated  to  a  slight  depth 
under  the  clasp,  and  filled  with  gold.  This  is  best  done  by  making 
a  few  retaining-pits,  filling  them  with  a  hand-plugger,  and  then 
inserting  the  main  body  of  the  gold  in  the  ordinary  manner,  the 
Herbst  method  being  useful  in  condensing  the  foil.     Such  a  filling 


236 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


inserted  at  any  time  will  prevent  injury  from  a  clasp.     A  denture 
of  this  style  can  be  made  to  pass  intervening  teeth. 

In  the  artificial  replacement  of  the  lower  teeth  in  a  case  such  as 
is  illustrated  in  Figs.  434,  435,  a  plate  bridge  possesses  many  ad- 
vantages. In  the  construction  of  such  a  denture,  the  teeth  are  first 
properly  shaped.  Grold  crowns  (Fig.,  437),  with  sides  as  nearly 
as  possible  parallel  the  one  with  the  other,  are  then  made  and  fitted 
to  the  bicuspid  and  molar.  This  operation  is  frequently  facili- 
tated by  shaping  the  external  surface  of  the  crown  with  metal. 

Fig.  436. 


Tig.  437. 


On  the  crowns,  at  the  buccal  sides,  a  narrow  shoulder  (A)  is  con- 
structed to  sustain  the  collars  and  bridge  in  position.  In  some 
cases  this  shoulder  is  placed  on  the  approximal  side  to  better  ad- 
vantage. Collars  B,  B,  Fig,  436,  reaching  from  the  cervical  to 
the  occluding  edge,  are  fitted  to  these  crowns. 

The  collars,  though  fitting  accurately,  should  move  easily  over 
the  crowns,  as  they  can  be  readily  tightened  when  the  case  is 
finished.  If  the  collar  is  troublesome  to  adjust  and  remove,  cut 
the  side  opposite  to  that  attached  to  the  plate,  and  spring  it  open 
a  little.  After  fitting  the  teeth  it  can  be  again  united  when  they 
are  being  soldered.  This  collar  and  shoulder  form  a  support 
in  some  respects  preferable  to  a  partial  or  an  entire  double  cap, 
being  less  difiicult  to  keep  clean.  A  collar  is  more  easily  con- 
structed, and  also  permits  the  position-  of  the  bridge  to  be  altered 
by  the  removal  of  a  little  of  the  shoulder  or  of  the  upper  edge  of 


REMOVABL]-:  I'LATK  BRIDd E-WORK. 


237 


the  collar,  and  is  a  secure  but  less  rigid  attachment  than  is  pro- 
vided by  other  methods.  The  other  constructive  details  of  this 
denture  are  conducted  in  accordance  with  the  method  previously 
described. 

The  attachment  of  the  artificial  teeth  to  a  plate  of  this  kind 
can  be  of  either  gold  or  rubber.  Whichever  is  adopted,  the  first 
bicuspid  is  best  supported  by  being  soldered  to  the  collar.  If 
iridio-platinum  is  used  in  the  construction  instead  of  gold  plate, 
and  the  soldering  done  with  pure  gold,  porcelain  body  can  be  used. 
When  ready  to  be  inserted,  the  crowns  are  adjusted  with  cement, 
and  then  the  bridge,  which  is  left  in  position  until  the  cement  sets. 
By  burnishing  the  collars  they  can  be  made  to  clasp  the  crowns 
as  firmly  as  desired.      Fig.  438  shows  the  dentin-e  in  position. 

Fig.  488. 


rigs.  439  and  440  represent  an  upper  removable  plate  bridge. 
In  its  construction  the  cuspid  roots  are  first  capped,  tubed,  and 
pivoted,  and  the  molars  crowned.  The  plate  intended  to  connect 
the  abutments  is  then  adjusted  in  position  as  has  been  described. 
An  impression  is  next  taken  and  a  model  made.  The  cuspids 
are  then  double-capped  and  collars  formed  on  the  molar  crowns. 

The  molar  collars  are  first  soldered  to  the  plate.  The  molar 
crowns  are  removed  from  the  model,  placed  in  the  mouth,  and  the 
collars  on  the  plate  fitted  over  them.  The  plate  is  pressed  firmly 
against  the  tissues,  and  the  line  of  the  edge  of  the  collars  toward 
the  gum  margin  marked  with  a  sharp  instrument  on  the  buccal 
surfaces  of  the  gold  crowns.  At  the  lines  marked  shoulders  are 
next  soldered  such  as  are  described  at  A,  Fig.  437.  The  plate 
and  all  the  caps  are  then  adjusted  in  the  mouth.  The  plate  is 
pressed  firmly  against  the  tissues,  the  double  caps  on  the  cuspids 


238 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


attached  with  cement,  or  plaster  instead  can  be  placed  over  them 
and  the  adjacent  surface  of  the  plate,  and  plate  and  cuspid  double 
caps  removed  and  soldered  together.  The  artificial  teeth  are  at- 
tached with  vulcanite,  the  gum  section  being  formed  with  pink. 
In  order  to  avoid  any  warping,  which  might  readily  occur  in  the 
construction  of  so  large  a  denture  as  this,  the  plate  may  at  first  be 
swaged  up,  as  in  ordinary  artificial  dentures,  to  cover  the  entire 

Fig.  439. 


Fig.  440. 


hard  palate.  A  shallow  groove  can  be  made  around  the  palatal 
surfaces  of  the  teeth,  and  after  the  final  soldering  the  plate  can  be 
cut  along  the  line  of  this  groove,  the  portion  covering  the  palate 
being  removed.  The  groove  will  insure  a  close  fit  for  the  palatal 
edge  of  the  plate. 

In  the  case  represented  in  Fig.  441  the  natural  teeth  were 
very  short.  The  posterior  approximal  side  of  the  molar  was 
decayed  to  such  an  extent  that  the  pulp  was  nearly  exposed,  and 
considerable  irritation  of  the  investing  gum-tissue  had  been  caused 


REMOVABLE  PLATE  BRIDGE-WORK. 


239 


by  the  clasp  of  a  plate  worn  by  the  patient  working  upward  against 
it.     The  patient  declined  to  have  a  plate  made  which  would  ex- 


FiG.  441. 


tend  across  the  palate.     The  lateral  was  hardly  strong  enough  to 
support  a  permanent  bridge.     The  molar  was  capped,  and  a  re- 


240 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


movable  appliance  constructed  with  a  band  which  slipped  over 
the  cap  and  rested  on  a  shoulder  on  the  mesial  side  to  form  the 
posterior  abutment.  The  lateral  was  notched  and  clasped  for  the 
anterior  support.  Figs.  442  and  443  are  two  views  of  the  appli- 
ance in  position.^ 

Fig.  444  represents  a  case  in  which  the  bicuspids  and  a'  molar 
are  replaced,  and  also  a  central,  on  an  extension  of  the  plate, 

Fig.  44-i. 


Fig.  445. 


the  cuspid  being  partly  encircled  by  a  clasp  with  a  shoulder  rest- 
ing on  the  palatal  section  of  the  tooth.  Fig.  445  shows  the  den- 
ture in  position. 

Fig.  446  represents  a  case  in  which  a  bridge-plate  was  inserted 
without  crowning  either  of  the  abutments.  The  clasp  of  a  plate 
which  had  been  worn  for  some  years  had  worked  upward  and 
abraded  the  distal  section  of  the  cuspid  to  such  an  extent  as  to 
expose  a  large  portion  of  the  root  and  superinduce  decay.  The 
cavity  was  filled  with  gold,  and  the  gingival  border,  by  treatment, 
brought  nearly  to  its  normal  position  on  the  tooth.  A  plate 
bridge,  such  as  is  represented  in  Figs.  447  and  448,  was  then  con- 
structed.    Clasps,  with  flanges  resting  on  little  shoulders  formed 

^This  denture  at  the  time  of  writing  has  been  worn  thirteen  years. 


REMOVABLE  I' I. ATE  BRIDGE-WORK. 


241 


at  A,  A,  Fig,  446,  support  and  retain  it.  A  flange  such  as  was 
used  in  this  case  is  best  made  subsequent  to  the  construction  of  the 
plate  and  clasps,  by  burnishing  a  piece  of  platinum  foil  in  the 
mouth  to  the  form  of  the  shoulder  and  the  side  of  the  tooth  upon 
which  it  is  to  rest,  adjusting  the  clasp  over  it,  and  cementing  with 
wax,  then  removing,   investing,   and  soldering.     "Wherever  the 


Fig.  447. 


Fig.  448. 


Fig.  449. 


platinum  is  placed,  the  solder  will  flow  and  fill  all  the  space  be- 
tween it  and  the  clasp.  This  gives  the  clasp  the  exact  form  of  the 
tooth. 

Fig.  449  shows  the  denture  finished  and  in  position.  If  the 
teeth  are  dense  in  structure,  an  attachment  of  metal  held  in 
proper  position  against  the  lower  portion  of  a  crown  will  be  worn 
a  long  while  before  it  causes  injury  to  the  parts.  Filling,  or 
crowning,  if  necessary,  can  be  resorted  to  subsequently. 

By  a  correct  application  of  the  methods  just  explained  and 
illustrated,  a  piece  of  removable  bridge-work  of  this  style  can 
be  devised  for  many  cases. 

17 


242 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Dr.  J.  L.  Davenport  describes  the  methods  he  adopted  in  the 
application  of  plate  bridges  to  the  following  case: 

"The  patient  was  a  gentleman  about  fifty-five  years  of  age. 
The  upper  jaw  contained  the  six  front  teeth,  the  three  molars 
on  the  right  side,  and  the  first  bicuspid  on  the  left.  The  lower 
jaw  contained  all  but  the  left  central  incisor,  the  second  bicuspid, 
the  three  molars  on  the  right  side,  and  the  first  and  third  molars 
of  the  left. 

"In  consequence  of  this  lack  of  occluding  back  teeth,  mastica- 
tion had  been  performed  solely  by  the  front  teeth,  causing  attri- 
tion so  great  on  the  upper  ones  as  to  entirely  obliterate  their 

Fig.  450. 


crowns,  while  the  lower  ones  suffered  but  little  loss,  as  will  be 
seen  by  reference  to  Fig.  450. 

"The  patient  had  managed  for  a  long  time  to  masticate,  though 
imperfectly,  upon  these  stumps,  but  latterly  could  eat  scarcely  any- 
thing but  soups  and  soft  foods. 

"The  restoration  of  the  lower  teeth  being  completed  to  the 
extent  of  about  one-eighth  of  an  inch  on  an  average,  to  make 
them  of  uniform  height,  my  attention  was  directed  to  the  upper 
incisors  and  cuspids,  nearly  all  of  which  I  found  with  dead  pulps, 
.and  some  of  them  in  a  condition  of  active  abscess. 

"The  two  superior  cuspid  roots  were  dressed  down  nearly  to 
the  gum,  and  fitted  with  22-carat  gold  cap-crowns.  After  these 
had  been  placed  in  position,  a  hole  was  drilled  through  each  cap 
of  a  size  suited  to  that  of  the  pulp-canal,  and  a  tube  of  iridium 


REMOVABLE  I'LATE  BRIDGE-WORK.  243 

and  platinum  was  adjusted  in  the  root  and  cap  and  waxed  in 
position.  The  cap  and  tube  were  then  taken  off  and  soldered, 
great  care  being  taken  to  have  the  tubes  enter  both  roots  per- 
fectly parallel.  These  were  permanently  secured  in  the  roots 
with  gutta-percha,  and  to  prevent  the  caps  being  pulled  off  the 
top  of  each  tube  was  slit  down  a  trifle,  and  after  insertion  was  bent 
back  into  the  gutta-percha  with  a  warm  instrument. 

''The  incisor  roots  having  been  dressed  down  even  with  the 
gum  and  filled,  a  plaster  cast  was  taken  and  a  narrow  20-carat 
gold  plate  was  swaged  to  fit  over  the  ends  of  the  incisors  and  the 
capped  cuspids,  making  it  a  little  broader  where  it  had  to  rest 
on  the  gum  back  of  the  first  left  bicuspid  root.  A  hole  in  the 
plate  was  then  made  to  expose  the  root  of  the  first  left  bicuspid. 
This  was  fitted  with  a  bifurcated  iridio-platinum  pin,  having 
notched  sides  and  a  hammered  head  upon  its  lower  end,  which 
came  down  below  the  root  about  three-eighths  of  an  inch. 

"A  thin  iridio-platinum  band  was  then  made  to  encircle  the 
root,  passing  just  under  the  gum  and  being  slightly  longer  than 
the  headed  pin.  This  band  was  perforated  with  two  rows  of 
holes,  from  without  inward,  giving  the  inner  surface  a  rough- 
ness similar  to  that  of  a  nutmeg-grater.  The  band  and  pin  were 
then  made  secure  to  the  root  with  a  non-shrinkable  copper  amal- 
gam. 

"Fig.  451  shows  the  upper  jaw  ready  for  the  plate. 

"After  the  amalgam  had  become  hard  and  the  end  and  sides 
had  been  polished,  a  gold  crown  was  fitted  over  all  just  up  to 
the  margin  of  the  gum,  and  in  close  contact  with  the  end  of  the 
band  and  amalgam.  This  crown  was  loose  enough  to  admit  of 
its  sliding  on  and  off,  though  with  just  enough  friction  to  hold  it 
in  place  when  at  rest.  This  gold  crown  was  then  placed  in  posi- 
tion, the  plate  also  inserted,  and  hard  wax  used  to  fij-mly  join 
the  two  in  the  mouth.     They  were  then  removed  and  soldered. 

"Gold  pins  were  then  placed  through  holes  drilled  in  the  plate 
into  the  tubed  cuspids;  then  soldered  to  the  plate,  the  pins  being 
of  a  size  to  fit  the  tubes  accurately.  The  plate  was  also  provided 
with  a  wide  clasp  encircling  the  first  molar  on  the  right. 

"The  plate  was  then  provided  with  a  gold  bar  about  one-eighth 
of  an  inch  wide,  occluding  perfectly  with  the  lower  teeth,  and 
plain  teeth  soldered  in  place,  hiding  the  bar,  and  just  meeting 


244 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


the  gum  in  front  of  tlie  incisor  roots.  The  plate  rested  squarely 
against  the  capped  cuspids,  each  of  which  showed  a  narrow  band 
of  gold  when  the  plate  was  in  position.  As  finally  completed 
(see  Fig.  452),  this  was  the  most  perfectly  fitting  piece  I  ever 


Fig.  451. 


•i  i'  'it 
I. 


inserted,  requiring  great  care  in  its  removal,  and  yet  by  a  little 
practice  the  gentleman  was  able  to  remove  and  replace  it  quite 
easily.     It  was  also  as  firm'  as  any  permanent  bridge  could  have 


Fig.  452. 


been,  though  it  had  no  support  on  the  left  side  back  of  the  first 
bicuspid. 

"The  lower  jaw  was  supplied  with  a  double  20-carat  gold  plate,, 
having  a  wide  clasp  on  the  first  right  bicuspid,  which,  after  being 
built  up.  presented  a  cone-shaped  top,   about  which  the  clasp 


REMOVABLE  PLATE  JIRIDG E-W'ORK. 


245 


fitted  so  as  to  rest  firmly  upon  the  end  of  the  tooth,  thus  pre- 
venting injury  to  tlie  gum  during  mastication. 

"The  only  other  peculiarity  was  that  the  second  left  inferior 
molar,  being  abnormally  short,  though  well  formed  and  standing 
straight  upright,  was  fitted  with  a  wide  clasp,  extending  almost 


Fig.  453. 


one-eighth  of  an  inch  about  the  tooth,  and  a  piece  of  gold  plate 
with  gold  cusj)s  was  soldered  into  this  clasp,  covering  the  molar 
crown  and  occluding  with  the  molar  on  the  upper  plate   (see 


Fig  454. 


'   Mil  I  II     1 


Fig.  453).  This  not  only  prevented  the  plate  from  being  bitten 
down  unpleasantly  on  the  gums  during  mastication,  but  enabled 
me  to  use  a  shorter  molar  upon  the  upper  than  I  otherwise  could 
have  done,  and  allowed  better  the  antero-posterior  and  lateral 
movements  of  the  jaws. 

"Fig.  454  shows  the  case  as  completed." 


CHAPTEK   XII. 

SPECIAL   FOEMS   OF   DETACHABLE   AND   KEMOVABLE 
BEIDGE-WOEK. 

A  DESCRIPTION  of  spocial  forms  and  methods  of  constructing 
detachable  and  removable  bridge-work  is  given  in  the  following 
pages,  as  practiced  by  the  introducers. 

DR.   WINDER'S  SECTIONAL  CROWN    METHOD. 

This  method  presents  the  novel  feature  of  constructing  the 
crowns  and  forming  the  abutments  in  sections,  the  bridge  being 
attached  to  the  dptachable  section. 

Fig.  455. 


Fig.  455  illustrates  a  case  of  bridge-work  made  in  this  manner. 
The  collar  section  of  the  artificial  crown  is  capped  and  cemented 
on  the  natural  crown  or  root,  the  gold  forming  the  occluding 
portion  of  the  crown,  when  the  bridge  is  adjusted  in  position, 
being  secured  to  it  with  a  screw.  The  screw  may  be  made  to 
enter  the  body  of  the  crown  as  in  Fig.  456,  or  it  may  be  soldered 
to  the  cap  on  the  collar,  passing  through  the  occluding  section 
of  the  crown,  and  being  secured  by  nuts  on  the  screws  (Fig.  457). 

In  constructing  a  bridge  of  this  style,  the  crowns  forming  the 
abutments  having  first  been  made,  are  removed  from  the  mouth 
in  a  plaster  impression  and  articulation,  from  which  a  model 
is  made,  showing  the  crowns  in  position.  Each  section  of  the 
bridge  between  the  crowns  is  then  constructed,  and  the  crowns 
246 


DETACHABLE  AND  REMOVABLE  BJll])GE-\\< )Il K. 


'247 


adjusted  in  the  mouth.  The  bridges  are  next  inserted  in  posi- 
tion, and  cemented  with  resin  and  wax  to  the  detachable  sections 
of  the  crowns.  The  whole  is  then  removed  in  investing  material, 
in  an  impression-cup,  or  by  placing  the  investing  material  in 
position  on  the  bridge.      After  being  removed  from  the  mouth 

Fig.  450. 


more  investing  material  is  added  and  the  bridge  and  crown  sec- 
tions soldered  together.  Only  the  detachable  sections  of  the 
crowns  should  be  in  the  investment  at  the  time  of  soldering. 

The  incisive  edges  can  be  protected  and  the  occluding  surfaces 
of  the  porcelain  capped  with  gold  as  in  permanently  attached 

Fig.  4.-)7. 


bridge-work,  or  they  can  be  formed  of  the  porcelain,  which  latter 
lessens  the  labor  of  construction,  as  the  bridge  is  easily  detached 
from  the  abutments  for  the  purpose  of  repair.  When  the  oc- 
cluding surfaces  of  bicuspids  or  molars  forming  the  bridge  are 
to  be  capped  with  gold,  the  collar  sections  alone  are  first  made 
and  removed  in  the  impression.  The  caps  for  the  crowns  and 
the  bridge  teeth  are  then  formed  of  one  continuous  piece  of  gold 


248  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

plate.  This  is  made  by  laying  the  strip  of  gold  on  a  piece  of 
lead  and  stamping  along  its  length  with  suitable  dies  representing 
the  occluding  surfaces  of  the  different  teeth.  The  gold  is  then 
properly  fitted  to  the  collar  sections  on  the  model,  conforming 
to  the  occlusion  of  the  antagonizing  teeth.^  The  cusps  are  filled 
with  solder,  and  the  porcelain  fronts,  backed  with  platinum  plate, 
are  fitted  in  position  to  the  gold  forming  the  caps  and  the  backings, 
cemented  with  w^ax,  removed,  invested,  and  soldered  to  the  caps. 
When  the  bridge  is  finished  the  root  and  collar  section  of  each 
crown  is  first  cemented  on  in  position  in  the  mouth ;  the  surface  of 
the  detachable  section  of  the  crown  approximating  the  section 
fastened  to  the  bridge  is  then  heated  and  the  surface  covered  with 
a  mere  film  of  gutta-percha.  The  bridge  is  then  adjusted  in  posi- 
tion and  secured  by  the  screws  or  nuts.  The  gutta-percha  pre- 
vents the  secretions  invading  the  interstices  between  the  sections 
of  the  crown. 

Fig.  458.  Fig.  459. 


Pig.  458  illustrates  another  method,  devised  by  Dr.  W.  E. 
Spencer,  of  constructing  the  sections  of  the  crowns  in  this  style 
of  bridge-work.  The  part  A  slides  in  the  groove  B.  The  dove- 
tail flange  A  is  made  of  a  thick  piece  of  plate,  fitted  to  the  groove 
B,  and  riveted  to  a  piece  of  platinum  adapted  transversely  across 
the  cap  and  then  soldered  to  the  removable  section  of  the  crown. 
Fig.  459  shows  the  section  of  the  crown  in  position. 

Pig.  460  illustrates  a  bridge  made  by  Dr.  C.  L.  Alexander,  in 
which  dovetail  slides  are  placed  on  the  sides  of  the  crowns. 

In  either  of  these  forms  gutta-percha  can  be  used  to  securely 
attach  the  bridge  so  that  it  shall  be  detachable  only  by  the  dentist. 

^In  the  Hollingsworth  System  will  be  found  another  method  of  constructing 
the  grinding-surfaces  of  a  number  of  crowns  and  dummies  of  one  piece  of  plate. 


DETACJIABLK  AND  REMOVABLE  BlilDGE-WOIih'.  £49 

An  advantage  possessed  by  these  styles  of  bridge-work  is  the 
facility  they  afford  for  the  ready  utilization  of  irregular  teeth  as 

Fig.  400. 


abutments,  no  matter  how  much  they  converge  or  diverge,  or 
lean  in  and  out  of  the  line  of  the  arch. 

DR.   LITCH'S   METHOD. 

Dr.  Litch's  method  of  constructing  detachable  bridge-work  con- 
sists in  forming  a  shell  anchorage  over  posts  permanently  fixed  in 
cuspid  roots,  and  anchoring  the  ends  of  the  bridge  with  bars  in 
slots  formed  in  natural  or  artificial  crowns. 

Figs.  461,  462,  and  463  illustrate  a  bridge  similar  to  the  one 
illustrated  in  Fig.  284  (page  159)  with  this  style  of  attachment 
applied.  The  anchorage  for  the  cuspids  is  constructed  as  follows: 
The  root  is  first  capped  and  pivoted  as  for  a  collar  crown.  On  the 
palatal  portion  of  the  collar  is  soldered  a  flange  (A,  Fig.  464) 
made  of  gold,  'No.  16  U.  S.  standard  gauge,  beveled  off  to  the 
upper  edge  of  the  collar  under  the  free  edge  of  the  gum,  the 
object  being  to  give  a  larger  surface  to  the  top  of  the  cap.  On 
this  cap,  which  covers  the  end  of  the  root,  the  anchorage  post  B, 
which  is  formed  of  iridio-platinum  v/ire,  No.  9  U.  S.  standard 
gauge,  is  soldered,  over  and  back  of  the  pin  (C)  which  enters 
the  root-canal,  so  as  to  allow  room  for  the  porcelain  front  D. 
The  porcelain  front  is  ground  in  proper  position  on  this  cap, 
backed,  attached  with  resin  and  wax,  and  removed  with  the  cap. 
The  cap  is  next  invested  in  plaster  to  the  edge  of  the  collar,  and 
a  little  plaster  is  placed  on  the  labial  aspect  of  the  porcelain  front 
in  the  form  of  a  matrix,  so  as  to  allow  the  porcelain  to  be  removed 
and  replaced.     A  piece  of  heavy  iridio-platinum  plate  (E),  No. 


250 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


16  TJ.  S.  standard  gauge,  is  then  shaped  into  the  form  of  a  half- 
ring,  with  the  ends  of  the  plate  against  the  backing  of  the  porcelain 
front,  and  of  sufficient  size  to  rest  on  the  flanged  edge  of  the  cap 


EiG.  461. 


Fig.  463. 


Fig.  462. 


Fig.  464. 


when  completed.  On  the  outside  of  this  half-ring  is  fitted  and 
soldered  a  thin  strip  of  gold  (F)  of  ^o.  28  U.  S.  standard  gauge, 
which  will  cover  the  half -ring  and  extend  beyond  its  cervical  mar- 
gin, slightly  overlapping  the  flange  of  the  collar  (G).  This  forms 
a  brace  or  edge  on  the  anchorage  cap  as  it  rests  on  the  root-cap. 


DETACH Alif.K  AM)  11 KMOVAJUJ-:  Jil{ID<J i:-\\> >l! K. 


251 


Fig.  4t;."). 


The  lialf-ring  is  then  fitted  to  tlie  tooth,  attaclied  with  wax,  and 
removed  with  the  tooth  out  of  tlie  phister  matrix  from  the  root- 
cap,  invested,  and  securely  soldered  on  the  inside  to  the  Ijacking 
of  the  tooth.  The  tooth  and  lialf-ring  are  then  adjusted  to  the 
root-cap,  over  the  post  of  which  the  ring  must  slide  easily  (Fig. 
465).  To  this  ring  the  bridge  is  soldered  the  same  as  to  a  crown. 
When  tlie  bridge  is  inserted,  the  cap  for  the  root,  with 
the  post,  is  first  cemented  on  with  oxyphosphate. 
After  the  cement  has  set,  the  anchorage  ring  is  filled 
with  more  cement  and  pressed  into  position  upon  the 
cap  over  the  anchorage  post*  The  surface  of  the 
cement  (H,  Fig.  404)  can  be  protected  by  a  metallic 
filling. 

This  form  of  attachment  permits  the  bridge  to  be 
easily  removed  by  affording  access  to  the  cement 
around  the  pin.  The  bar  ends  of  the  bridge  are  anch- 
ored in  the  crowns  with  gold  or  amalgam  fillings, 
Avhich  likewise  are  not  difficult  to  remove. 

The  anchorage  cavity  for  a  bar  in  a  gold  molar  crown 
for  use  over  a  tooth  Avitli  a  living  pvilp  is  best  made  by 
cutting  out  the  gold  to  the  form  of  the  slot  required,  and  inserting 
in  its  place  a  piece  of  platinum  of  the  shape  of  the  walls  of  the 
anchorage  cavity.  The  crown  is  then  filled  with  investing  ma- 
terial, and  the  metal  forming  the  anchorage  cavity  soldered  to 
the  crown  at  the  edo'es  of  the  cavity. 


DR.   R.   W.   STARR'S    METHODS. 

Dr.  E.  Walter  Starr  gives  the  following  descriptions  of  his 
methods  in  detachable  bridge- work: 

"The  case  of  Mr,  W.  presented  difficulties  of  an  unusual  char- 
acter, as  may  be  seen  by  inspecting  the  illustration  (Fig.  466), 
which  renders  detailed  description  unnecessary. 

"^Tt  will  be  observed  that  the  molars  and  the  left  second  bicuspid 
overhang  to  a  degree  that  would  make  the  taking  of  an  accurate 
impression  by  ordinarj^  methods  well-nigh  impossible.  After  a 
careful  study  of  the  case,  it  was  decided  that  two  separate  pieces 
of  detachable  bridge-work  should  be  attempted,  and,  as  an  essen- 
tial preliminary  step,  the  overhanging  sides  of  the  molars  and 
bicuspids  were  ground  with  engine  corundum-wheels  and  points 


252 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 
Fig.  466. 


Fig.  467. 


DETACIIABLK  A\D  JiEMOVABLK  BRIDGE-WORK. 


253 


until  tliose  sides  were  made  much  less  inclined,  when  plaster  im- 
pressions were  taken,  first  of  one  half,  and  then  of  the  other  half, 
of  the  jaw.  Gold  cap-crowns  were  closely  fitted  over  the  molars, 
left  second  bicuspid,  right  first  bicuspid,  and  cuspid  stump.  Gold 
crowns  were  made  to  telescope  over  all  the  caps,  which  were  then, 
by  means  of  oxyphosphate  cement,  fixed  firmly  on  the  teeth. 
Suitable  plate  teeth  were  selected,  fitted,  backed,  and  hard-waxed 
in  place  between  the  telescoping  crowns.     After  hardening  the 

Fig   408. 


wax  with  cold  water  from  a  tooth-syringe,  the  pieces  were  care- 
fully removed,  invested,  and  soldered.  The  two  completed 
bridges  were  easily  replaced  on  or  removed  from  the  supporting 
capped  teeth,  and  their  appearance  when  detached  is  correctly 
shown  by  the  illustration,  Fig.  467,  which  also  shows  the  capped 
teeth  and  stumps.  The  figure  likewise  shows  the  results  of  the 
novel  method  employed  in  crowning  the  incisors.  Gold  collars 
were  fitted  tight  on  the  necks  of  the  incisor  stumps,  and  the  porce- 
lain caps  adjusted  in  the  collars,  and  set  in  the  oxyphosphate 
cement  which  had  been  packed  into  the  collars;  thus  at  the  same 
time  fastening  the  collars  on  the  stumps  and  the  caps  in  the  col- 
lars, as  shown  completed  in  Figs.  467  and  468. 


254  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

"Fig.  468  illustrates  the  finished  crowns  and  bridges,  which 
latter  were  secured  in  position  by  placing  a  small  piece  of  gutta- 
percha in  each  of  the  telescoping  cap-crowns,  which  were  then 
warmed  and  carefully  pressed  in  place, — the  gutta-percha  filling 
only  the  spaces  between  the  flat  tops  of  the  caps  of  the  natural 
teeth  and  cusped  caps  of  the  bridges. 

"Whenever,  for  repair  or  for  any  other  purpose,  it  shall  be- 
come  desirable  to  remove  one  of  the  bridges,  that  may  readily 
be  done  by  applying  a  hot  instrument  or  hot  air  to  the  caps  to 
soften  the  gutta-percha  sufficiently  to  permit  the  telescoping 
bridge  to  be  taken  off. 

"A  full  upper  vulcanite  denture  was  made  to  replace  the  old 
one,  which,  by  improper  occlusion,  had  thrown  the  full  force  of 
mastication  on  the  anterior  teeth  of  the  lower  jaw,  and  produced 
the  destructive  action  that  resulted  in  the  deplorable  loss  of  tooth- 
substance  shown  in  Fig.  466."  ^ 

The  next  case  also  presented  unusual  difficulties.  "The  for- 
ward overhang  of  the  inferior  right  second  molar  was  so  excessive 
that  an  impression  could  hardly  be  taken,  until  with  corundum- 
wheels  and  points  the  sides  of  the  tooth  had  been  made  parallel,  or 
rather  slightly  tapering  to  form  a  truncated  cone,  with  the  neck 
as  a  base.  The  molar  was  alive  and  sound,  but  the  crown  was 
gone  from  the  pulpless  cuspid,  which  I  suitably  shaped  by  means 
of  my  root-trimmers  (Fig.  469). 

"An  impression  was  then  taken,  the  cast  from  which  is  illus- 
trated by  Fig.  470.  A  seamless  gold-  collar  was,  by  means  of  a 
slightly  tapering  mandrel,  made  to  exactly  fit  the  tapered  natural 
molar,  the  lower  edge  of  the  collar  cut  to  conform  to  the  gingival 
margin;  a  cap  piece  of  gold  plate  soldered  to  the  top  edge  of  the 
collar,  and  a  hole  drilled  through  the  center  of  the  completed  cap 
(A).  Care  was  taken  to  so  fit  and  proportion  the  cap  that  it  would 
require  finally  pretty  hard  driving  to  send  it  home  on  the  tooth; 
but  first  there  was  fitted  to  the  cap  a  telescoping  seamless  collar, 
on  which  was  soldered  a  gold  plate,  with  cusps,  to  form  a  molar 
crown  as  shown.  The  molar  was  then  thoroughly  dried,  slightly 
painted  with  Agate  cement,  and  the  cap,  A,  driven  hard  down 
with  a  flat  pine  stick  held  upon  it  and  struck  with  a  mallet;  the 

'  Denial  Cosmos,  vol.  xxviii,  No.  1,  page  17. 


DETACH  A  BLK  AND  REMOVABLE  BRIDGE-WORK. 


255 


hole  in  the  cap  enabling  me  to  see  when  the  cap  was  quite  down. 
The  cuspid  was  then  likewise  fitted  with  a  seamless  gold  collar, 
the  top  edge  of  which  was  given  a  roof -shape,  as  seen  above  the 
root  in  Fig.  470.  A  piece  of  gold  received  a  corresponding  roof- 
shape,  had  a  short  section  of  gold  tubing  soldered  into  it,  and  was 
trimmed  to  the  outline  of  the  collar,  beside  which,  B,  its  form  is 
seen,  and  to  which  it  was  subsequently  soldered,  after  suitable 
investment  to  keep  the  parts  in  proper  place.  The  root-canal  had 
been  previously  prepared  to  receive  the  tube,  which,  with  its 


roofed  caj),  was  with  stick  and  mallet  driven  hard  down  over  the 
root.  A  piece  of  gold  wire  exactly  fitting  the  tube  had  a  roof- 
shaped  piece  of  properly  perforated  gold  plate  slipped  over  it  into 
position  on  the  root;  became  fixed  in  such  relation  by  a  drop  of 
melted  hard  wax;  was  removed,  invested,  soldered,  and  finished 
in  such  shape  that,  excepting  the  hoUowness,  it  looked  like  the 
tube  and  cap  B. 

"The  relations  of  the  occluding  teeth  had,  of  course,  been 
determined  by  an  articulating  model,  and  by  means  of  it  a  series 
of  seamless  gold  collars  and  cusp-crowns  were  adjusted  on  a  thin 
platinum  plate  fitted  on  the  cast  between  the  cuspid  and  second 
molar,  and  the  collars  soldered  to  the  plate  after  investment.  The 
truss  thus  formed  received  an  appropriate  finish  by  the  rounding 


256 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


and  smootliing  of  its  basal  borders.  A  plain  plate  cuspid  was 
backed  with  gold  plate  and  fitted  on  tbe  roof -plate,  to  wbicli,  after 
determining  its  proper  occlusion,  it  was  secured  by  hard  wax;  re- 
moved, invested,  and  soldered.  It  was  then  put  into  the  tube  on 
the  root;  the  telescoping  cap  put  over  the  molar;  the  truss  put  in 
position  in  the  mouth,  and  the  whole  covered  with  plaster  and 
marble-dust,  contained  in  a  suitable  sectional  impression-tray,, 
which  enabled  me  to  hold  the  mass  steadily  in  place  until  the  mix- 
ture was  sufficiently  hard  to  bring  away  cap  and  truss  and  roof- 
plate  all  in  proper  position.     A  second  mixture  of  plaster  and 

Fig.  471. 


marble-dust,  and  a  suitable  trimming  of  the  first  mixture  after  all 
was  hard,  sufficed  for  the  soldering  process  that  resulted  in  the 
denture  which,  when  finished,  appeared  as  shown  detached  at  C, 
rig.  4Y0,  and  mounted  on  the  cast  in  Fig.  471.  It  went  firmly 
to  place  in  the  mouth,  and  yet  was  removable  in  the  possible 
event  of  accident  to  the  denture,  or  for  readjustment  of  the  cusp- 
crowns,  which  latter  could  easily  be  done  by  warming  the  piece 
sufficiently  to  soften  the  gutta-percha,  replacing  the  denture  on  its 
anchorages,  and  directing  the  proper  closure  of  the  occluding 
teeth." 

DR.  PARR'S    METHODS. 

Detachahle.—Yig.  472  illustrates  a  method  of  this  style.  The 
teeth  forming  the  abutments  lean  toward  each  other  posteriorly 
and  anteriorly  over  the  space  to  be  bridged,  as  shown  on  the 
original  model,  Fig.  4Y3.  The  bridge  is  supported  by  two 
shoulders  on  the  abutment  crowns,  which  slide  into  grooves  in 


DKTACHABLK  AND  RKMOVABLK  BRWr^JJ-WORK. 


257 


the  dummies  (Fig.  474).  These  supporting  shoulders  and  slots 
are  made  by  shaping  two  pieces  of  platinum  plate  to  the  form 
shown  in  Fig.  475,  so  that  one  shall  telescope  the  other.  The 
inner  one  is  then  invested  on  the  outside  surface  and  filled  in 
with  gold  plate.  The  outer  piece  is  then  filled  inside  with  in- 
vesting material,  and  gold  plate  is  flowed  over  the  outer  surface. 
The  shoulders  are  first  soldered  to  the  crowns,  and  afterward  the 
slots  are  adjusted  to  them  and  soldered  in  position  in  the  bridge. 


Fio.  473. 


Fig.  474. 


Fig.  475. 


Fig.  476  shows  a  bridge  constructed  with  the  attachment  de- 
scribed at  one  end  and  a  double  cap  attachment  at  the  other.^ 

Removable  Bridge. — In  this  style  the  crowns  forming  the  abut- 
ments are  permanently  cemented  in  position,  each  section  of  the 
bridge  between  them  being  removable.  The  case  illustrated  in 
Fig.  477  will  serve  as  a  type  to  give  the  constructive  details. 
The  cuspid  and  molar  crowns  are  first  formed  in  the  usual  man- 
ner. A  model  from  an  impression  is  then  made,  on  which  the 
crowns  will  appear  in  the  same  position  as  in  the  mouth.  A  gold 
and  platinum  bar  (A,  Fig.  478)  is  then  formed  between  the 
cuspid  and  molar.     The  end  for  the  cuspid  is  rounded,  and  that 


^  Case  of  Dr.  C.  L.  Alexander,  described  page  27,  Dental  Cosmos,  vol.  xxxiii. 

18     . 


258 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


for  the  molar  flattened.  This  last  may  be  done  by  hammering 
the  wire  flat  or  by  soldering  a  piece  of  clasp  plate  transversely 
to  it.  The  two  ends  of  the  bar  are  then  fitted  in  sockets  of 
platinum  (B,  B).     The  ends  of  the  bar  should  be  bent  and  the 

Fig.  476. 


platinum  sockets  placed  in  such  a  position  against  the  sides  of 
the  crowns  that  the  bar  can  be  easily  adjusted  and  removed. 
The  sockets  are  next  soldered  to  the  sides  of  the  cuspid  and 
molar  crowns  (A,  A,  Fig.  477),  for  which  purpose  the  sockets 


Fig.  477. 


and  crowns  should  be  removed  and  invested.  The  sockets  are 
held  in  position  when  the  wax  is  melted  out  by  pieces  of  iron 
wire,  one  end  of  which,  covered  with  a  portion  of  the  investing 
material,  is  inserted  in  the  socket,  the  other  end  being  imbedded 
in  the  investment.  If  preferred,  the  slot  on  the  side  of  the 
molar  crown  can  be  made  with  a  piece  of  platinum  adapted  over 


DF/rAt'IIABLE  AND  REMOVABLE  BRIDGE- WORK. 


259 


the  flat  piece  of  gold  forming  the  end  of  the  bar,  and  then 
soldering  the  platinum  to  the  side  of  the  crown,  the  platinum 
being  stiffened  bj  flowing  the  solder  over  it.  At  this  point  the 
crowns  and  bar  may  be  adjusted  in  the  mouth,  as  well  as  on  the 
model,  to  insure  accuracy.  A  piece  of  thin  platinum  or  gold  is 
then  perforated  and  slipped  over  the  ends  of  the  bar,  which  is 
jDlaced   in   position   on   the   crowns,    and   the   platinum   or   gold 


Pig.  478. 


adapted  to  the  form  of  the  attachments,  and  to  the  immediately 
adjacent  surfaces  of  the  crowns.  These  shell  forms  are  made  to 
assure  to  the  ends  of  the  bridge  a  perfect  fit  by  giving  them  the 
shape  of  the  crowns  and  the  attachments  on  the  crowns.  To 
this  bar  the  teeth  constituting  the  bridge  are  fitted  in  their 
respective  positions  and  soldered.  Bending  either  end  of  the 
bar  slightly  (B,  B,  Fig.  477),  or  sawing  a  slit  in  the  cuspid  end 

Fig.  479. 


of  it  (Fig.  409),  affords  the  means  of  holding  the  bridge  firmly  in 
position,  although  it  may  be  removed  and  reinserted  at  the  option 
of  its  wearer.     Fig.  479  shows  the  inserted  bridge. 

Fig.  480  shows  another  method  of  forming  a  socket  attach- 
ment. In  the  figure,  the  socket  section  of  the  attachment  is 
seen  projecting  from  the  side  of  the  molar  crown.  The  other 
section  consists  of  a  cap  having  a  spring  flange.  The  flange 
enters  the  socket,  which  the  cap  incloses  on  the  top  and  at  the 
sides.  The  spring  is  made  by  bending  open  a  little  the  part 
of  the  flange  marked  A. 


260 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


This  form  of  attachment  is  constriicted  as  follows:  To  make 
the  spring  flange,  two  pieces  of  clasp  or  spring  gold  plate  about 
1^0.  23  U.  S.  standard  gauge,  one  of  them  one-half  and  the  other 
one-fourth  of  an  inch  long  and  from  one-eighth  to  one-quarter  of 
an  inch  wide,  the  exact  dimensions  being  governed  by  the  case  in 
hand,  are  laid  together,  so  that  one  end  of  the  short  piece  is  nearer 
one  end  of  the  larger  piece  than  the  other.  The  edge  of  the  short 
piece  nearest  the  end  of  the  longer  one  is  then  soldered  to  it  with 
a  hard-flowing  solder,  the  two  being  held  during  the  operation 
in  a  blue  gas  flame  with  tweezers,  and  the  end  is  trimmed  square. 
A  little  whiting  placed  between  the  other  edges  will  prevent  the 
solder  from  flowing  between  or  joining  the  pieces  there.  The 
short  piece  of  plate  is  to  form  the  spring,  and  is  left  unconnected 
at  one  end  for  that  purpose  (A,  Fig.  481). 

To  Form  the  Socket. — The  spring  flange  is  flrst  enveloped  once 
around  with  a  thin  piece  of  platinum,  a  little  deeper  than  the 
socket  is  required.     The  platinum  is  then  enveloped  with  one 

thickness  of  coin  gold  plate,  ISTo.  32 
U.  S.  standard  gauge,  about  the  depth 
the  socket  is  to  be,  leaving  a  ledge  of 
the  platinum  projecting.  The  plati- 
num and  gold  are  next  removed  and 
soldered,  by  holding  them  in  a  flame 
and  using  very  little  solder,  of  a  hard- 
flowing  variety,  which  is  placed  upon 
the  ledge.  The  sides  and  ends  of 
the  sockets  are  then  filed  level  and 
the  socket  given  a  square  form  (B). 
To  Form  the  Cap.- — The  spring  flange  having  been  inserted 
in  the  socket,  two  pieces  of  the  spring  gold  plate  of  the  same 
length  as  the  socket  are  adjusted  along  its  sides,  the  pieces  being 
cut  a  little  wider  than  the  depth  of  the  socket,  so  that  when 
adjusted  they  shall  project  slightly  above  it.  A  piece  of  thin 
platinum  plate  is  then  adapted  to  the  end  of  the  flange,  to  the 
socket,  and  to  the  pieces  of  spring  plate,  first  being  perforated 
to  allow  the  projecting  ends  of  the  latter  to  pass  through  it.  The 
spring  plates  and  the  flange  plate  are  then  cemented  to  the  plati- 
num plate  with  wax,  removed  from  the  socket,  invested,  and  sol- 
dered (C). 


DKTACIIABLK  AXD  REMOVABLE  BRIDGK-WORh'.  Ogl 

The  sockets  must  be  so  placed  on  the  crowns  that  the  springs 
at  the  ends  of  the  bridge  shall  enter  them  on  parallel  lines. 
Their  proper  relative  positions  to  secure  this  movement  are  readily 
determined  by  attaching  the  tops  of  the  spring  flanges  (either 
temporarily  or  permanently)  to  the  ends  of  a  piece  of  wire  of  the 
length  of  the  space  to  be  bridged,  which  will  permit  the  neces- 
sary adjustment.     The  sockets  are  then  soldered  onto  the  crowns. 

When  the  bridge  teeth  or  dummies  adjoining  the  sockets  have 
been  fitted  in  position,  they  are  withdrawn  with  the  caps  and 
spring  flanges,  and  soldered  to  the  bar,  in  the  manner  described 
at  page  258.  The  gold  caps  forming  the  occluding  surfaces  of 
the  bridge  tooth  can  usually  be  fitted  over  the  cap.  When  the 
socket  is  attached  lengthwise  from  labial  to  palatal  side  to  a  gold 
crown  as  at  A,  Fig.  477,  the  spring  metal  plate  of  the  flange  is 
best  placed  on  the  side  toward  the  crown. 

In  a  bridge  of  this  style  of  the  anterior  teeth  only, — where  the 
abutments  form  the  extremities  of  the  piece, — the  ends  should 
be  attached  to  the  mesial  sides  of  the  crowns  forming  the  sup- 
ports; but  when  it  also  carries  teeth  posterior 

to  the  abutment,  and  the  sections  of  the  bridge       ^^- 

are  united  together,  the  attachment  should  be 
made  on  the  distal  side,  the  bar  supporting  the 
anterior  teeth  resting  in  a  slot  formed  on  the 
palatal  side  of  the  abutment  (Fig.  482).  A  shell 
crown  on  a  cuspid  can  be  utilized  as  a  support 
for  this  form  of  attachment. 

The  attachment  described  can  also  be  used  in  combination 
with  removable  plate  bridges. 

Fig.  483  shows  the  cast  of  a  lower  jaw  in  which  only  the  left 
second  molar,  left  cuspid,  and  right  first  bicuspid  remained. 
The  molar  and  bicuspid  were  fitted  with  gold  cap-crowns,  and 
spring  socket  attachments  (Dr.  Parr's  form)  were  soldered  in 
proper  positions  on  the  crowns,  as  illustrated.  The  completed 
denture  in  position  supported  by  the  attachments  is  seen  in  Fig. 
484.     The  under  side  is  shown  in  Fig.  485. 

Fig.  486  represents  the  articulated  cast  of  a  case  in  which  a 
similar  form  of  attachment  and  a  clasp  were  used.  This  is 
illustrated  in  Fig.  487,  which  needs  no  description. 


262 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  483. 


Fig.  484. 


^  :r  r  X  > 


Fyi    18^ 


DF/PA  CIL I  BIj  /<;  .  I XD  RKMO  VA  BLE  BRIDU  E-  W()RK. 


263 


Fig.  488  shoAVs  the  denture  in  place.     It  was  constructed  of 
vulcanite,  and  made  for  and  placed  in  the  mouth  of  a  patient 


Fig.  48r,. 


Fio.  481 


Fig.  488. 


exhibited  at  a  clinic  of  the  Odontological  Society  of  Pennsyl- 
vania, at  Philadelphia,  in  December,  1888.^ 

DR.   WATERS'S    METHODS. « 

Dr.  T.  S.  Waters  explains  the  advantages  of  his  removable 
plate  bridge-work  as  follows:  "In  the  system  I  present  the  denture 
is  retained  securely  and  steadily  in  the  mouth,  yet  is  readily  re- 
moved and  replaced  at  pleasure  by  the  wearer.  The  pressure 
and  strain  are  distributed  properly  over  all  the  structures  and  tis- 
sues available  for  the  purpose,  and  the  roots  and  crowns  to  which 
the  denture  is  attached  are  so  prepared  that  there  is  no  place  for  the 
lodgment  and  retention  of  food,  and  when  the  denture  is  removed, 
both  it  and  the  mouth  can  be  thoroughly  cleansed.  Should  the 
roots  or  other  tissues  be  attacked  by  disease,  thus  requiring  treat- 
ment, or  should  repairs  to  the  mechanism  become  necessary,  the 
movable  bridge-work  offers  facilities  for  those  purposes  not  to  be 
found  in  permanent  dentures." 


^Dental  Cosmos,  March,  1881). 

'■^  International  Dental  Journal,  April 


1881),  page  197. 


264 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Dr.  Waters  thus  describes  the  formation,  combination,  and 
application  of  his  devices  to  cases  of  removable  plate  bridge-work : 

"My  devices  are  three  in  number,  each  of  which  may  be  used 
alone,  or  two  of  them  or  all  three  may  be  combined  and  applied 


Fig.  489. 


Fig.  490. 


Fig.  491. 


i  f 


/^ 


in  the  same  case,  as  the  position,  character,  and  relation  of  the 
teeth  and  roots  remaining  in  the  mouth  may  seem  to  indicate. 
"The  iirst  is  a  gold  crown  fitted  to  and  sliding  on  a  cap  attached 
permanently  to  the  root '  or  natural  crown.  This  cap  is  made 
high  and  has  on  one  side  a  longitudinal  groove.  The  gold  crown 
has  soldered  on  the  inside  a  spring  catch,  which  works  in  the  groove 
on  the  cap,  and  holds  the  crown  firmly  in  its  place.  The  char- 
acter of  the  device  is  seen  in  application  to  the  case  represented  in 


DETACJIABLE  AND   KKMOVABLE  BRIDfiE-WORK. 


205 


Fig.  489.  Fig.  490  shows  the  denture  in  position.  Fig,  491 
gives  the  lingual  aspect.  It  will  be  readily  seen  that  under  proper 
circumstances  two  or  more  roots  or  teeth  may  be  fitted  with  this 
device,  the  gold  crown  may  be  soldered  to  and  made  a  part  of  the 
denture,  making  the  whole  a  piece  of  bridge-work  capable  of  being 
removed,  cleaned,  and  replaced  at  will.  The. spring  catch  regu- 
lates the  firmness  of  retention.^ 


Fig.  493. 


Fig  494 


"The  next  device  is  the  box  cap  and  split  post;  the  box  cap 
being  fitted  permanently  to  the  root,  and  the  split  post  being 
soldered  to  the  plate  bearing  the  teeth.  The  box  cap  is  the  usual 
cap,  with  a  box  or  tube  soldered  to  it  and  extending  into  the 
root,  the  cap  end  of  the  tube  being  open.     The  split  post  is  so 

^Dr.  "Waters  has  patented  this  invention  and  donated  it  to  the  profession. 


266 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 


secured  to  the  denture  as  to  slide  snugly  into  this  tube,  the  firm- 
ness of  retention  being  regulated  by  pressing  the  split  slightly 
open  when  necessary.     This  device,  like  the  first,  may,  under 


Fig.  495. 


proper  circumstances,  be  used  by  itself  in  any  case,  as  shown  in 
application  in  Mgs.  492,  493,  and  494,  in  which  the  whole  denture 
is  supported  by  box  caps  and  split  posts  adjusted, to  the  roots  of 
the  six  anterior  teeth. 


DETACH  ABLE  AND  REMOVABLE  BRIDGK-]V'<)I{K.  Ofjy 

"The  third  device  consists  in  soldering  to  the  side  of  the  gold 
croM'n  covering  the  natural  tooth  a  split  pin  or  post,  which  is 
inserted  into  the  open  tube  attached  to  the  denture. 

"As  before  remarked,  these  devices  may  be  used  singly  or  in 
combination  in  any  one  case.  In  one  of  the  dentures  illustrated 
the  box  cap  and  split  post  alone  are  used;  in  another,  the  cap, 
gold  crown,  and  spring  catch  are  used;  in  the  case  illustrated  in 
Figs.  495,  496,  and  497  the  three  are  applied,  in  which  the  entire 
denture  is  attached  to  and  retained  by  two  cuspids,  a  bicuspid, 
and  a  molar.  In  all  this,  great  care  must  of  course  l)e  taken  in 
the  prej^aration  of  the  roots  and  natural  crowns,  to  protect  them 
against  the  action  of  destructive  agents." 

DR.    BONWILL'S    METHOD. i 

The  special  feature  of  this  method  is,  the  advocacy  of  con- 
necting the  clasp  attachment  to  the  plate  with  a  piece  of  stout 
gold  and  platinum  wire  on  the  side  of  the  tooth,  offering  the 
least  resistance  to  the  insertion  and  removal  of'  the  clasp.  This, 
for  instance,  should  be  on  the  buccal  side  of  a  lower  molar  if  it 
tips  inward  or  forward.  The  clasp  is  thus  left  free  to  spring 
over  any  portion  of  the  crown  out  of  line. 

The  clasp  is  surmounted  with  a  flange  or  spur  placed  at  a  point 
free  of  the  occluding  teeth,  and  the  plate  is  made  of  lieavy  gold 
plate  or  of  two  thin  plates  soldered  together.  A  description  of  the 
following  practical  cases  will  explain  the  method: 

Fig.  498  is  a  cast  for  the  first  upper  bicuspid,  right  side.  A 
filling  of  gold  was  placed  in  the  distal  surface  of  the  natural 
cuspid,  with  a  hole,  c,  drilled  into  the  filling  for  the  pin  c.  Fig. 
499.  The  second  bicuspid  had  also  a  large  amalgam  filling, 
around  which  the  clasp  was  placed,  so  that  it  would  not  show 
from  the  mouth.  Fig.  499  shows  the  plate  with  a  tube-tooth' or 
porcelain  crown  thereon,  Avith  pin  soldered  to  the  plate.  The 
clasp  has  a  flange  attached  to  it  at  7i.  -^  is  a  heavy  platinized 
gold  bar,  showing  how  it  forms  a  free  attachment  between  plate 
and  clasp,  c  is  a  pin,  soldered  directly  to  the  plate,  which  enters 
the  hole  in  the  gold  filling  shown  at  c  in  Fig.  498. 

Fig.  500  is  a  skeleton  plate  with  the  attachments  without  the 
tooth  made  for  the  case — left  side,  lower  jaw — shown  in  Fig.  502. 

'^International  Dental  Journal^  vol.  xiv,  page  94. 


268 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


e  and  e,  Fig.  500,  are  flanges  to  prevent  the  plate  pressing  too 
hard  on  the  gum.  One  rests  on  the  molar  independent  of  the 
clasp,  and  the  other  on  the  bicuspid.  A  small  spur  is  placed 
under  the  flange  that  is  to  rest  on  the  bicuspid  to  fit  in  a  groove 
in  an  amalgam  filling  shown  at  d,  Fig.  502,  to  keep  the  anterior 
portion  of  the  plate  in  position.  The  clasp  is  connected  to  the 
plate  at  the  lingual  side  bj  the  bar  marked  i.  Fig.  501  shows 
the  finished  case  with  the  artificial  crown  cemented  over  the  pins 
or  vulcanized  on. 


Fig.  498. 


Fig.  499. 


Fig.  500. 


Fig.  501. 


Fig.  502. 


Fig.  503. 


Fig.  503  shows  the  replacement  of  a  second  bicuspid,  right 
side,  lower  jaw.  The  bar  i  is  soldered  to  the  plate  and  clasp 
on  the  buccal  side  of  the  first  molar.  The  artificial  tooth  is 
made  entirely  of  gold,  and  the  flange  resting  on  the  first  bicuspid 
is  soldered  directly  to  it.  The  anterior  surface  of  the  gold  tooth 
is  made  concave  to  fit  the  distal  surface  of  the  first  bicuspid,  and 
so  prevent  lateral  movement. 

In  this  case  a  gold  crown  is  used  as  the  artificial  tooth,  as  it 
facilitates  the  soldering,  adds  to  the  strength,  is  easy  to  repair, 
and  is  not  seen.  The  rear  flange,  which  rests  on  the  molar,  might 
have  been  soldered  to  the  gold  tooth  also,  and  less  strain  would  thus 
come  on  the  clasp. 


CHAPTEK    XIII. 

REMOVABLE  BAR-BRIDGES. 

In  removable  bar  bridge-work  the  bar  is  permanently  attached 
to  the  abutments,  and  spans  the  space  between  them  independent 
of  the  bridge.  The  bridge  portion  proper  of  the  denture,  con- 
sisting of  the  artificial  teeth  (dummies),  is  formed  with  a  slot,  or 
a  countersunk  base,  into  which  the  bar  slides  as  the  bridge  is 
placed  in  position. 

EiG.  504. 


In  the  case  represented  in  Fig.  504,  one  end  of  the  bar  is 
attached  to  the  gold  molar  crown  and  the  other  end  anchored 
in  the  cuspid  with  a  gold  filling.  The  bridge  section  fits  over 
the  bar  as  illustrated.  The  process  of  construction  as  given  by 
Dr.  J.  G.  Morej  is  as  follows : 

The  molar  is  capped  with  gold.  A  flat  bar  of  iridio-platinum, 
about  ISTo.  12  gauge  and  one-eighth  of  an  inch  wide, — ^the  width 
being  regulated  by  the  needs  of  the  case  in  hand,- — is  fitted  to  the 
space.  One  end  of  the  bar  is  fitted  in  the  anchorage  cavity  in  the 
cuspid,  and  the  other  end  to  the  gold  molar  crown.  A  slot  ia 
then  cut  in  the  bar,  beveled  slightly  toward  the  gum  (Fig.  504). 

A  piece  of  gold  clasp  plate,  about  ^o.  28  gauge,  the  width  of 
the  slot,  is  cut  and  shaped  in  the  form  of  a  clamp  to  fit  over  both 
sides  of  the  bar  in  the  slot.  The  end  of  the  bar  is  then  sol- 
dered to  the  gold  crown.     The  bar  must  be  placed  far  enough 

•IC,'.) 


270  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

toward  the  palatal  side  to  leave  space  for  the  artificial  teeth. 
Porcelain  teeth  are  liext  fitted  in  place,  backed  with  thin  plati- 
num, cemented  with  Avax  to  the  clamp-shaped  piece  of  gold, 
and  removed  from  the  bar.  Teeth  and  gold  clamp  are  then  in- 
vested and  soldered  together.  In  investing,  one  end  of  a  narrow 
strip  of  sheet  iron  is  inserted  in  the  slot  of  the  gold  clamp,  and 
the  other  end  extended  into  the  body  of  the  investment,  to  hold 
and  steady  the  gold  clamp  in  position,  while  the  gold  solder  is 
flowed  between  it  and  the  porcelain  tooth  after  the  wax  is  re- 
moved.    When  finished,  the  point  of  the  gold  clamp  is  to  be  bent 


a  little  inward  to  secure  and  fasten  tlie  bridge  section  when  slid 
into  position  on  the  bar.  Firmness  is  also  obtained  by  the  slightly 
beveled  form  given  to  the  slot  in  the  bar.  Kg.  505  gives  a  sec- 
tional side  view  of  the  bridge-tooth  and  bar.  Fig.  506  represents 
the  bar  and  bridge  section  in  position.^ 

Dr.  Morey's  method  of  constructing  a  double  bar-bridge  with 
a  removable  molar  or  dummy  is  as  follows : 

The  bar  is  formed  as  seen  in  Fig.  507.  "A  countersunk  molar 
is  ground  and  shaped  as  seen  at  A  and  B,  Fig.  508.  To  the  base 
of  the  molar  and  up  in  the  slot  is  shaped  and  fitted  the  shell  C, 
made  of  a  very  thin  piece  of  gold  and  platinum  crown-metal  by 

1  A  description  of  a  removable  bar-bridge,  as  given  by  Dr.  J.  G.  Morey,  was 
presented  in  the  first  and  second  editions  of  this  work.  A  more  extended  descrip- 
tion of  bridge-work  on  this  principle  is  given  in  the  later  editions,  as  many  mem- 
bers of  the  profession  seem  to  favor  the  various  methods  it  involves.  In  England 
the  method  is  designated  the  "  Gartrell  Bridge,"  having  been  introduced  there  by 
Dr.  Gartrell,  an  American  dentist,  formerly  of  New  York,  now  practicing  at 
Penzance,  England. 

The  models  of  a  case  similar  to  the  one  illustrated  in  Figs.  504  and  506  were 
exhibited  at  the  Ninth  International  Medical  Congress  at  Washington  and  pre- 
sented by  Dr.  Morey  to  the  author  in  1887,  and  are  still  in  his  possession ;  but,  as 
the  method  did  not  favorably  impress  him  at  ihe  time,  further  description  of  it 
than  had  been  given  was  withheld. — G.  E. 


i 


JIKMO  VA r,LE  I:A  li-l'.l(lD<iES. 


271 


£rst  stamping  it  on  a  fusible  metal  die  of  the  base  and  then 
adapting  it  to  the  part.  A  thin  piece  of  clasp-metal  CD)  is  then 
formed  to  fit  over  the  bar  and  in  proper  position  into  the  slot  of 
the  shell  (C,  Fig.  507),  to  which  it  is  fastened  by  investing  and 
soldering  on  the  inside  of  the  shell.  The  shell  is  then  cemented 
with  oxyphosphate  onto  the  base  of  the  molar  as  seen  at  A  and 
B,  Fig.  507,  and  is  secured  to  the  bar  by  springing  together  the 
edges  of  the  metal  at  D,  Fig.  508.  Fig.  509  illustrates  the  tooth 
in  position." 


Fig.  oOT 


Fig.  o08. 


Fig.  '^V.s. 


f^ff^i 


A  variation  in  the  method  of  construction  of  removable  bar- 
bridges  involving  the  principle  above  demonstrated  is  given  by 
Dr.  G.  L.  Curtis  in  the  following  case,  illustrated  in  Fig.  510. 
The  bicuspid  and  molar  are  capped  with  gold,  and  models  made. 
In  the  construction  of  the  dummies,  the  caps  and  backing  at  first 
are  merely  joined  together  with  solder  just  sufficient  to  prevent 
movement  of  the  caps.  The  sockets,  like  A,  Fig.  511,  which  are 
made  of  thin  gold,  are  then  placed  in  position  and  held  by  means 
of  fluxed  wax,  and  the  entire  piece  again  encased  as  before,  so 
that  the  ends  of  the  sockets  project  beyond  the  cusp-surface  of 
the  bridge  and  are  imbedded  in  the  plaster,  which  holds  them 
in  position.  The  wax  is  melted  out  and  the  sockets  soldered 
into  place.     After  r-ooling,  the  projecting  parts  of  the  sockets 


272 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


are  cut  away  -until  tlie  bridge  fits  perfectly  between  tbe  crowns^ 
and  the  soldered  surface  is  ground  away  to  the  proper  fullness, 
and  the  whole  piece  rendered  quite  smooth  or  ready  for  polishing 
(C,  rig.  510).  Arms  like  B,  Fig.  511,  are  now  placed  into  the 
sockets  and  cut  off  until  a  perfect  adjustment  with  the  crown  is 


Fig.  510. 


Fig.  511. 


1)1  A 


Fig.  512. 


Fig.  513. 


obtained.  It  will  be  found  that  the  arms  are  considerably  wider 
than  the  sockets  are  deep,  allowing  them  to  project  one-sixteenth 
of  an  inch  or  more.  Secure  the  bridge  in  position  by  a  drop 
of  wax  at  the  junction  of  the  porcelain  surface  and  the  cast, 
then  varnish  the  palatal  surface  of  the  cast  and  pour  soft  plaster 
and  marble-dust  over  the  surface  until  it  is  on  a  level  with  the 
masticating  surface,  and  allow  it  to  harden.  Then  carefully  re- 
move the  bridge  and  replace  the  arms  in  position  as  marked  in 


REMO  VABLK  BA B-BRW(.ES. 


273 


the  plaster,  and  retain  them  by  means  of  additional  plaster,  or 
by  steel  springs,  and  solder  them  to  the  crowns,  first  placing  in 
the  joint  sufficient  fluxed  wax  so  that  in  the  process  of  soldering 
the  arms  will  be  perfectly  united  to  the  crown,  which  requires  a 
very  small  quantity  of  solder.     The  case  is  new  ready  to  finish. 


Fig.  514. 


If  the  adjustment  of  arm  and  socket  is  perfect,  the  structure 
will  be  found  to  fit  so  snugly  that  it  is  only  with  considerable 
effort  that  the  bridge  can  be  removed.  With  every^;hing  in  readi- 
ness for  cementing,  the  crowns  are  quickly  forced  into  position, 
the  bridge  carried  to  place,  and  the  cement  allowed  to  harden. 

Should  any  alteration  be  necessary  in  the  articulation  that 

cannot  be  made  by  grinding  ofl'  the  cusps  of  the  antagonizing 

teeth,  the  bridge  can  readily  be  removed  without  disturbing  the 

crowns. 

19 


274  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

The  arm  B,  Fig.  511,  is  made  of  a  strip  of  clasp-metal,  ISTo. 
16  gauge  in  thickness,  and  of  any  desired  width  or  length.  The 
strip  is  placed  in  a  slot  like  E,  Fig.  512,  and  the  projecting  end 
hammered  to  form  a  solid  head  as  shown.  A  longer  or  shorter 
arm  may  be  formed  in  the  slot  F,  wherein  the  adjustable  limit, 
G,  may  be  set  to  mark  the  length  of  the  arm  while  the  hammered 
head  is  being  formed.  A  piece  of  20-carat  gold  plate,  or  pref- 
erably clasp-metal  ISTo.  33  gauge,  is  cut  to  the  size  and  shape  of 
Fig.  513,  and  by  means  of  a  former,  K,  Fig.  512,  is  forced  into 
a  suitable  slot.  The  place  of  the  former  K  is  then  taken  by  the 
arm  B,  Fig.  511,  and  the  part  H,  Fig.  512,  bent  and  delicately 
hammered  over  the  head  of  the  arm.  The  socket  so  formed  is 
then  removed,  soldered  from  the  outside,  and  finished  as  at  A, 
to  exactly  fit  the  arm  B,  Fig.  511. 

Figs.  514  and  515  illustrate  a  case  by  Dr.  Parr,  in  which  a 
removable  bar-bridge  plate  was  applied. 


CHAP  TEE    XIV. 

DR.  KNAPP'S  METHODS. 

De.  J.  RoLLO  Knapp  has  introduced  some  novel  methods  in 
crown-  and  bridge-work,  for  effecting  artistic  results  and  con- 
tinuity of  structure. 

In  crown-work,  Dr.  Knapp  invests  for  soldering  so  that  the 
parts  to  be  united  and  filled  form  a  miniature  mold.  Into  this 
mold,  at  a  high  heat,  with  a  pointed  flame  from  his  blow-pipe, 
he  flows  solder,  which  fills  the  interstices,  joins  the  parts,  and 
assumes  the  form  of  the  mold.  The  following  is  a  brief  descrip- 
tion of  his  methods: 

Fig.  516.  Fig.  517. 


In  constructing  a  gold  collar  crown  with  porcelain  front,  for 
an  ihcisor  or  cuspid,  22-carat  collar  gold  (The  S.  S.  White  Dental 
Mfg.  Co.'s),  'No.  28  standard  gauge,  is  used  for  the  collar,  which  is 
formed  by  adapting  the  gold  to  the  root  by  the  aid  of  pliers.  The 
cap  to  the  band  is  then  made  of  pure  gold,  ISTo.  34  gauge,  and  a 
gold  pin  is  soldered  in  position  for  the  root-canal.  A  plate  tooth 
is  then  ground  in  proper  position,  backed  with  pure  gold,  and 
fastened  to  the  cap  with  wax.  On  being  removed  from  the  mouth 
after  proper  adjustment,  the  side  and  incisive  portions  of  the  wax 
including  the  edges  of  the  backing  and  contiguous  portions  of 
the  cap,  are  completely  enveloped  with  pieces  of  pure  gold  No. 
34  gauge  (Figs.  516  and  517).  The  crown  is  then  invested  so 
that  when  the  wax  is  removed  the  backing  on  the  tooth  with  the 

275 


276 


ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 


gold  on  the  sides  shall  form  a  small  mold  or  pocket  (Figs.  518 
and  519).  When  the  investment  is  heated,  the  flame  of  his 
blow-pipe  is  played  over  its  surface  until  the  mass  is  aglow,  when 
the  point  of  the  flame  is  thrown  into  the  mold  by  rapid  thrusts 
until  the  solder  melts  like  wax  and  fills  every  part  of  the  mold 
with  liquid  gold.  This  gives  an  excess  of  gold  which  affords 
ample  facilities  for  contouring  in  the  process  of  finishing  (Figs. 
520  and  521). 


Fig.  518. 


Fig.  519. 


Fig.  520. 


Fig.  521. 


In  constructing  a  bicuspid  crown  with  porcelain  face,  the 
natural  tooth  is  ground  down  to  the  gingival  edge  and  capped 
similar  to  a  cuspid.  A  bicuspid  porcelain  front  is  then  ground 
and  fitted  in  position  (Fig.  522),  and  the  remaining  portion  of 
the  crown  is  shaped  in  wax  to  the  form  required.     A  die  of  the 


Fig.  522. 


Fig.  52.3. 


Fig.  524. 


Fig.  525. 


Fig.  526.       Fig.  527. 


grinding-surface  is  then  made  in  metal,  a  cap  stamped  in  pure 
gold,  No.  34  U.  S.  standard  gauge  (Fig.  523),  and  the  cusps 
filled  with  20-carat  gold  solder.  This  cap  is  next  trimmed  (Fig. 
524)  so  as  to  fit  when  placed  in  proper  position  against  the  end 
of  the  porcelain  cusp,  for  which  purpose  sufficient  wax  must  be 
removed.  The  approximal  surfaces  are  enveloped  and  the  palatal 
portion  of  the  collar  protected  with  pieces  of  pure  gold,  E"o.  34 
standard  gauge,  which  are  slit  to  facilitate  their  adjustment  (Fig. 
525).     This  leaves  the  palatal  portion  open  when  the  crown  is 


DR.  KNArrKs  METHODS. 


277 


invested  and  the  wax  removed,  v^^hich  last  should  be  done  with 
hot  water.  Fig.  526  shows  the  invested  crown  ready  for  soldering, 
in  which  operation  the  parts  are  filled  in  and  joined  with  20-carat 
gold  solder.  The  result  when  finished  is  a  solid  gold  crown  with 
a  porcelain  front  (Fig.  527). 

Dr.  Knapp's  method  of  constructing  bridge-work  is  similar  to 
that  in  general  use  except  in  the  investing  and  the  soldering  to- 
gether of  the  parts,  the  latter  being  done  with  the  blow-pipe  in  a 
manner  similar  to  that  above  described. 

Figs.  528  and  529  illustrate  specimens. 


Fig.  528. 


Fig.  529. 


Dr.  Knapp's  compound  blow-pipe  (Fig.  530)  consists  of  a 
miniature  blow-pipe  in  which  the  ordinary  illuminating  gas  (car- 
buretted  hydrogen  or  coal  gas)  flame  is  combined  with  a  current 
of  nitrous  oxid  from  a  cylinder  of  the  condensed  gas.  The  com- 
bination of  these  gases  in  combustion  forms  essentially  a  carbo- 
oxyhydrogen  flame.-^  By  means  of  a  yoke  and  set-screw,  the  valve 
of  the  cylinder  is  connected  with  the  tubes  and  valves  of  the  blow- 

^The  ordinary  compound  oxyhydrogen  blow-pipe  flame  is  produced  by 
2  volumes  of  hydrogen  ;  1  volume  of  oxygen. 

Carburetted  hydrogen  consists  of 

2  volumes  of  hydrogen  ;  1  volume  of  carbon. 

And  nitrous  oxid  of 

2  volumes  of  hydrogen  ;  1  volume  of  oxygen. 

Consequently  Knapp's  blow-pipe  flame  is  produced  by  a  mechanical  mixture  of 
2  volumes  of  hydrogen  ;  1  volume  of  oxygen  ;  1  volume  of  carbon. 


278 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


pipe,  so  that  the  proportions  of  the  mixture  of  nitrous  oxid  and  the 
illuminating  gases  are  under  perfect  control.  The  flame-jet  can 
be  diminished  to  half  an  inch  in  length,  and  at  that  size  will  melt 
a  small  piece  of  gold  plate. 


Tig.  530. 


Where  illuminating  gas  is  not  available,  an  apparatus  termed 
a  carburetter  can  be  used,  which  supplies  the  deficiency  in  a 
simple  manner  by  vaporizing  naphtha. 


DR.  KXAl'P'S  METHODS.  279 

This  blow-pipe  is  useful  for  many  pui^poses  in  the  laboratory 
of  the  present  time,  especially  in  forming  solid  gold  backings  to 
dummies  for  bridge-work,  strengthening  seamless  gold  crowns,  and 
forming  solid  gold  crowns. 

Dr.  Knapp  has  exhibited  to  the  profession  some  very  fine  speci- 
mens of  crown-  and  bridge-work,  and  presented  much  that  is 
novel  and  interesting,  as  well  as  encouraging  to  the  artistic  ele- 
ment of  prosthetic  dentistry.  His  special  methods,  however, 
while  admitting  of  the  highest  artistic  results,  embrace  some  pro- 
cesses which,  on  account  of  their  intricacy,  have  not  been  very 
generally  adopted  in  practice. 


CHAPTEK   XV. 

THE  MANDEEL  SYSTEM. 

In  all  styles  of  collar  crowns  the  shaping  and  adapting  of  the 
collar  is  usually  found  by  many  dentists  to  be  the  most  difficult 
part  in  their  construction.  To  facilitate  its  performance  the 
"Mandrel  System"  was  introduced  by  The  S.  S.  White  Dental 
Manufacturing  Co.^ 

"The  configuration  of  the  necks  of  all  the  teeth  having  been 
determined,  a  set  of  mandrels  for  shaping  collars  to  fit  them  was 
devised.  The  set  (Fig,  531)  consists  of  seven  tapering  mandrels, 
six  of  which  are  double  end,  representing  the  average  shapes  of 
the  necks  of  all  the  teeth.  The  illustrations  are  about  two- 
thirds  actual  size,  the  longest  instruments  being  nine  inches  in 
length.  The  cross-sections  show  the  shapes  and  proportionate 
sizes  at  the  greatest  and  least  diameters. 

"ISTo.  1  is  a  double-end  mandrel,  for  superior  molars,  right  and 
left;  'No.  2  is  a  single  mandrel,  for  superior  bicuspids,  right  and 
left;  ISTo.  3  is  double-end,  for  superior  cuspids,  right  and  left; 
ISTo.  4,  double-end,  for  superior  centrals,  right  and  left;  jSTo.  5, 
double-end,  for  inferior  molars,  right  and  left;  ISTo.  6,  double-end, 
for  the  inferior  centrals,  laterals,  cuspids,  and  first  bicuspids,  right 
and  left;  No.  7,  double-end,  one  end  for  the  superior  lateral  incisors, 
the  other  for  those  bicuspids  in  which  a  bifurcation  of  the  roots,  or 
a  tendency  in  that  direction,  extends  across  the  neck  to  the  crown 
in  the  form  of  a  depression  on  one  or  both  approximal  surfaces. 
The  foregoing  scheme  comprehends  all  the  teeth  of  the  permanent 
set  except  the  second  inferior  bicuspids.  The  necks  of  these  ap- 
proximate those  of  the  superior  central  incisors  so  closely  in  shape 
that  it  was  deemed  inexpedient  to  make  a  separate  mandrel,  as  the 
No.  4  mandrel  will  serve  for  both. 

^  Dental  Cosmos,  vol.  xxviii,  No.  8. 
280 


THE  MANDREL  SYSTEM.  281 

Fig.    531. 

FOR  SHAPIJVO  SEAMLESS  TOOTU-ROOT  COL.EARS. 


No.l. 


No.  2. 


No.  3 


No.  7. 


282 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


"The  collars  or  bands  are  made  seamless,  of  ISTo.  30  (Am.eri- 
can  gauge)  gold  plate,  22  carats  fine.  Fifteen  sizes,  eacli  of 
three  widths  (yV»  Aj  ^^^  i¥  inch)  are  made  (Fig.  533),  which, 
it  is  believed  will  cover  all  requirements.  These  collars,  although 
devised  as  a  part  of  the  system,  can  be  used  in  all  methods  of 
crown-  and  bridge-work  which  require  bands.  They  are  so  con- 
structed that  ISTos.  1,  16,  and  31  exactly  fit  into  or  telescope  with 
ISTos.  2,  17,  and  32,  and  so  on  through  the  entire  set,  each  collar 
fits  into  the  series  next  higher;  so  that  a  root  may  be  banded 
with  one  size  and  the  size  next  larger  used  to  form  the  tube  for 

Fig.  .>32. 


the  telescoping  crown.  When  desirable,  the  ^seamless'  collar  can 
be  strengthened,  after  being  adapted  to  the  conformation  of  the- 
crown,  by  investing  and  flowing  solder  over  the  outer  surface; 
or  by  fitting  the  next  larger  size  of  collar  around  the  first,  invest- 
ing and  soldering  the  two  together. 

"The  other  appliances  devised  for  this  system  are,  a  reducing- 
plate  or  contractor,  a  pair  of  collar  pliers,  and  a  hammer. 

"The  contractor  (Fig.  532)  contains  holes  which  are  comple> 
mentary  in  shape  to  the  mandrels.  The  mandrels  being  applied 
to  the  inner  circumferences  of  the  collars,  while  the  contractor 
must  admit  the  collars  themselves,  the  short  taper  of  the  holes 
in  the  contractor  necessarily  covers  a  somewhat  greater  range  of 
size  than  is  shown  in  the  mandrels.     With  this  appliance  collars 


TiiF.  ma.\'diii:l  system. 


283 


C3 

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as 
as 
as 
a§ 


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Fk;.   633. 


a« 


w 


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9> 


(t> 


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Vi 


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o 


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O 

O 

o 
o 


284 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


can  be  evenly  and  accurately  reduced  in  size  at  the  edges,  with- 
out burring  or  buckling.     The  illustration  is  actual  size. 

"The  collar  pliers  (Fig.  534)  are  for  contouring  the  collars  to 
shape,  one  beak  being  made  convex  and  the  other  concave  to 
correspond.  Fig.  535  is  a  mallet  or  hammer,  with  steel  face 
and  horn  peen. 


Fig.  534. 


Fig.  535. 


1 

! 


"To  select  and  adjust  a  suitable  collar  for  a  crown  or  root, 
take  a  piece  of  binding- wire  (ISTo.  28,  American  gauge),  two 
and  one-half  inches  long,  pass  it  around  the  neck  of  the  molar 
stump,  cross  the  free  ends,  and,  holding  the  wire  in  place  mth 
one  finger,  twist  the  ends  with  a  pair  of  flat-nose  pliers  until  the 
wire  clasps  the  neck  closely  at  every  point  (Fig.  536).     Where 


Fig.  536. 


Fig.  587. 


there  are  irregularities  in  the  contour  of  the  tooth,  it  is  necessary 
to  press  the  wire  into  them  with  a  burnisher.  The  ring  thus 
formed  will  show  the  exact  size  and  shape  of  the  neck  of  the 
tooth.  Eemove  the  ring  carefully,  lay  it  on  the  lead  anvil,  put 
over  it  a  piece  of  flat  metal,  and  with  a  smart  blow  from  a 
hammer  drive  the  wire  into  the  lead  (Fig.  537).  Upon  remov- 
ing the  wire,  an  exact  impression  of  the  ring  will  be  left  in  the 
anvil. 


THE  MAN  DUEL  SYSTEM. 


285 


"JSText,  cut  the  wire  ring  at  the  lap,  straighten  out  the  wire, 
and  select  a  suitable  collar  by  comparing  the  length  of  the  wire 
with  the  straight  lines  in  the  diagram  (Fig.  533),  which  show  the 
inside  diameters  of  the  various  sizes.  Should  none  of  these 
correspond  exactly,  take  preferably  the  next  size  smaller.  Having 
selected  the  collar,  fit  to  mandrel  with  the  peen  of  the  hammer, 
holding  it  upon  the  lead,  and  using  a  slight  pushing  force  to  help 
in  stretching  and  forming  it  (Fig.  538).     Having  driven  the  collar 


Fig.  539. 


Fig.  538. 


to  form,  remove  it  from  the  man- 
drel and  try  in  the  lead  impression. 
If  it  does  not  fit  exactly,  return  it 
to  the  mandrel  and  stretch  it  a 
little,  when  it  will  usually  fit  per- 
fectly. 

"If  the  collar  or  band  has  been 
accidentally  stretched  too  much,  or 
if  for  any  reason  it  is  too  large,  its 
root-end  can  easily  be  reduced  to 
the  proper  size  by  the  use  of  the  contractor.  Place  the  edge  of 
the  collar  which  is  to  fit  the  root  in  the  proper  hole;  hold  it  level 
with  a  piece  of  file  as  in  taking  the  lead  impression  of  the  ring, 
and  tapping  lightly  on  the  file  drive  the  collar  into  the  plate  (Fig. 
539)  until  the  proper  reduction  is  made."  The  collar  is  next 
trimmed  to  correspond  to  the  shape  of  the  gum-margin.  The  cap 
section  to  represent  the  grinding-surface  is  then  added  by  one  of 
the  methods  described  on  pages  83  and  88. 

The  grinding  section,  in  cases  of  pulpless  roots,  may  be  con- 
structed of  porcelain  by  the  use  of  porcelain  cusp-crowns,  such  as 
are  shown  in  Fig.  540.  Where  porcelain  is  to  be  used,  place 
the  collar  in  position,  and  having  ascertained  how  far  it  should 
go  down  on  the  root,  remove  it,  and  with  the  small  spring  punch 
in  the  collar  pliers  form  projections  on  the  inside  of  the  collar  at 
proper  points  to  serve  as  stops,  which,  by  resting  on  the  top  of  the 
root,  will  prevent  the  collar  from  being  forced  farther  down  on 


286 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


it  than  is  desirable  (Fig.  541).  ISText  fit  and  cement  screw-posts 
in  the  root-canals,  leaving  the  ends  projecting  in  the  space  inside 
the  collar,  and  cement  the  collar  on  the  root,  filling  about  two- 
thirds  of  the  depth  of  the  collar.  Select  a  suitable  cusp-crown, 
of  the  form  illustrated  in  Fig.  540,  and  fit  to  inside  of  end  of  collar. 
If  too  long,  shorten  the  cusps  or  reduce  the  length  of  the  collar. 

F]G   .')40 


Fig.  541. 


Ftg.  542. 


When  articulated,  form  a  small  square  shoulder 

around  the  line  of  the  edge  of  the  porcelain  with 

a  corundum  disk.     Fill  the  remainder  of  the  inside 

of  the  collar  with  cement,  mixed  to  a  cream-like 

consistence,  and  set  the  porcelain  in  position.     If 

there  are  antagonizing  teeth,  the  mere  closing  of  the 

patient's  jaws  will  force  the  cusp  to  position  in 

posterior  teeth.     In  the  front,  or  where  there  are  no  occluding 

surfaces,  force  to  position  with  the  mallet  or  a  piece  of  wood  as 

a  driver. 

Fig.  ;j43. 


Porcelain  cusp-crowns  of  the  form  shown  in  Fig.  542  are  in- 
tended for  use  where  the  labial  side  of  the  collar  is  cut  away, 
and  that  section  is  to  be  represented  by  the  porcelain  as  shown  in 


Fig.  543. 


CHAPTEE   XVI. 

THP]  HOLLINGSWORTH  SYSTEM. 

The  object  of  the  "Hollingsworth  System"  is  to  systematize 
and  simplify  the  process  of  construction  of  that  style  of  cro^vn- 
and  bridge-work  in  most  general  use.  To  this  end  the  form  of 
procedure  is  concisely  outlined  and  some  special  methods  and  ap- 
pliances introduced.  The  last  mentioned  consists  of  a  set  of  two 
hundred  and  four  forms  of  solid  metallic  grinding-surfaces  of  bi- 
cuspids and  molars,  termed  in  the  description  "cusp-buttons,"  for 
use  in  forming  grinding-surfaces  for  crowns  or  dummies;  thirty- 
six  facings  for  shaping  the  labial  surfaces  of  all-gold  bicuspid  and 
molar  dummies,  and  forty  for  labial  and  palatal  surfaces  of  all- 
gold  incisors  and  cuspid  crowns.  These  collectively  are  to  be 
seen  in  the  case  illustrated  in  Fig.  544;  likewise  (Fig.  544  A) 
some  other  appliances  contained  in  the  set.  A  brief  description 
of  the  principal  methods  in  connection  with  the  use  of  the  appli- 
ances is  here  given. 

TO    MAKE    A    GOLD    CROWN    (BICUSPID    OR   MOLAR). 

Make  a  band  to  fit  the  root  in  the  ordinary  way.  Place  the 
band  in  the  mouth  (see  Fig.  545),  and  cut  off  on  a  line  where 
the  adjoining  teeth  begin  to  turn  to  form  the  cusp  (see  c,  Fig.  545). 
Place  a  small  piece  of  wax  inside  the  band  to  assist  in  holding  the 
cusp-button,  which  should  be  selected  to  fit  the  circumference 
of  the  band,  to  articulate,  properly,  and  to  correspond  in  shape 
with  the  other  teeth  (see  h,  Fig.  545).  Remove  the  button,  and 
place  it  on  the  molding-plate  with  the  grinding-surface  up  (see 
Fig.  546).  Place  the  small  rubber  ring  around  it,  pour  in  a  suf- 
ficient quantity  of  Melotte's  metal  to  nearly  fill  the  ring  (Fig. 
547).  As  soon  as  the  metal  sets,  chill  the  surface  by  dipping  in 
water  for  a  moment,  and  then  remove  the  rubber  ring.  When 
the  heat  l)egins  to  return  to  the  surface,  a  quick  rap  of  the  die  on 

287 


288 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 

Fig.  544. 


yi  jf^^^'V 


t; 


Set  consists  of  the  following :  204  Cusps,  36  Facings,  40  Forms  for  Incisors  and  Cuspids,  in 
folding  case,  1  Casting  Plate  (A),  3  Rubber  Rings  (E,  F),  1  Carbon  Rod  (B),  1  Sheet  Asbestos 
10x7  in,  (C),  Boxof  Annealed  Copper  Strips  (D).    (See  Fig.  544  A.) 

the  bench  will  cause  the  cusp-button  to  drop  out  and  leave  the 
mold  ready  to  form  the  gold  cusp.  ISTow  take  a  piece  of  lead,  for 
instance  a  lead  hub,  and  with  a  hammer  drive  into  the  Melotte- 
metal  die  (Fig.  548)  to  form  the  counter-die  (Fig,  548,  d). 


Till-:  II<)IJ,IN<1S\\'()I{TII  Si  STEM. 


289 


Fig.  545 


Fig.  54 


EiG.  546. 


Fig.  548. 


Fig.  549. 


Fig.  550. 


Fig.  551. 


XII  (4 


20 


290 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Anneal  the  gold  plate,  and  start  the  swaging  process  by  coax- 
ing the  plate  into  the  die  by  hand-pressure  (Fig.  549),  using  a 
piece  of  wood  which  makes  a  depression  for  the  lead  counter- 
die  to  rest  in.  Then  place  the  counter-die  on  the  gold  plate 
(Fig.  550),  and  drive  to  a  fit.  Cut  the  surplus  metal  from  the 
hollow  cusp  with  shears  (Fig.  551),  filing  up  the  edges  when 
necessary,  and  rub  down  the  under  surface  on  a  smooth  file  until 
it  fits  the  band  made  for  it  (Fig.  545).  Wire  the  cusp  and  crown 
together  (Fig.  552),  place  flux  and  solder  in  the  cap,  and  hold 
over  a  lamp  until  soldered.  Then  finish  in  the 
usual  way. 


Fig.  552. 


Fig.  553. 


Fig.  554. 


c 


Note. — If  the  forms  of  cusp-buttons  do  not 
afford  one  which  articulates  perfectly,  the  diffi- 
culty is  easily  remedied  by  taking  the  button 
which  most  nearly  answers,  and  building  up  the 
cusps  with  Melotte's  moldine  (Fig.  553).  If  a 
band  is  accidentally  cut  too  short,  it  can  still 
be  utilized.  Place  moldine  upon  the  molding- 
plate,  put  the  cusp-button  upon  it,  press  down  and  adjust  to 
make  up  the  deficiency  of  the  band,  cutting  away  the  surplus 
moldine.  This  will  of  course  throw  the  soldering  line  a  little 
farther  up  on  the  crown  (Fig.  554). 

TO    MAKE    SOLID    GOLD    CUSPS. 

Scrap  gold  can  be  utilized  for  making  a  solid  gold  cusp  by 
casting  in  asbestos  by  the  following  method: 

After  selecting  the  desired  cusp-button,  instead  of  making  a 
mold  in  Melotte's  metal,  as  before  described,  take  a  piece  of  asbes- 
tos board  about  one  inch  square  and  one-fourth  inch  thick,  moisten 
it,  and  with  a  hammer  drive  the  cusp-button  into  it,  flush  with 
the  surface  of  the  button.     (See  Fig.  555,  a.)     Remove  the  but- 


THE  ITOLLIXasWOJiTH  srSTEM. 


291 


ton,  and  dry  the  asbestos  in  a  flame  (Fig.  655).  "When  perfectly 
dry,  place  a  sufiicient  quantity  of  gold  scraps  in  the  die  made  in  the 
asbestos,  and  direct  the  blow-pipe  flame  upon  it  until  melted,  in- 
clining the  carbon  stick,  as  shown,  against  the  die  for  the  double 
purpose  of  confining  the  heat  and  warming  up  the  carbon  stick. 
When  the  gold  is  fused  into  a  button,  press  it  into  the  die  with 
the  carbon  stick  (Fig.  556).  Avoid  the  use  of 
flux  when  ivorhing  with  asbestos. 

To  build  up  a  cusp  to  make  a  perfect  articu- 

FiG.  556. 


Fig.  555. 


lation,  in  this  method,  sealing-wax  must  be  used  instead  of  mold- 

ine,  as  in  swaging  the  cusp.     Warm  the  button  before  applying 
the  wax,  and  with  a  warm  instrument  shape  the  cusp  as  desired. 

TO    MAKE    GOLD    CROWNS    (CENTRALS,    LATERALS,    AND 

CUSPIDS). 

Select  from  the  forty  different  forms  in  the  set  that  which  is 
most  suitable  to  the  case  in  hand  (Fig.  557).  (The  forms  are 
in  pairs,  showing  labial  and  lingual  surfaces.)  Take  the  meas- 
urement of  the  root  to  be  crowned  with  one  of  the  annealed 
copper  strips,  binding  the  strip  around  the  tooth  with  pliers  (Fig. 
558,  a).  Take  this  measurement  and  cut  it  through  the  center 
(Fig.  558,  &),  then  bend  the  respective  halves  over  the  lingual  and 
labial  forms  selected,  at  the  necks,  with  the  cut  ends  of  the  strips 
Testing  on  the  flat  of  the  plate  (Fig.  559).  If  the  measurement 
is  larger  than  the  form  selected,  build  the  latter  up  vdth  moldine 
until  the  space  between  the  form  and  strip  is  filled  (Fig.  559,  &). 
Avoid  getting  moldine  on  the  approximal  surface.  Remove  the 
strips,  dry  out  the  moldine,  by  passing  through  a  flame  a  few  times, 
then  place  the  form  on  the  molding  plate  with  a  rubber  ring  around 


292 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


it.  Pour  Melotte's  metal  into  the  ring  as  in  forming  the  molar  or 
bicuspid  cusp,  which  makes  a  die  of  the  two  sections,  lingual  and 
labial.  Make  a  lead  counter-die  and  proceed  as  directed  in  the 
making  of  a  molar  cusp,  swaging  both  sections  (Fig.  560).  Trim 
off  the  surplus  plate  (Fig,  561),  and  square  the  opposing  edges 
of  the  two  sections  by  rubbing  them  over  a  dead  smooth  file. 


Fig.  557. 


Fig.  558. 


Pig.  559. 


Fig.  560. 


Fig.  561. 


Fig.  563. 


Fig.  564. 


Bind  the  two  sections  together  with  wire  with  sufficient  solder 
and  flux  inside  (Figs.  562  and  563),  and  proceed  as  in  soldering 
an  ordinary  band.  With  a  small  mechanical  saw  cut  off  the 
upper  portion  where  the  tooth  begins  to  slope  back  (about  the 
dotted  lines  in  Fig.  563).  This  leaves  the  crown  as  shown  in 
Fig.  564,  approximal  and  labial  views.     Drive  on  the  root.     If 


THE  NOLLINOSWO/mr  SYSTEM. 


293 


too  small,  place  on  the  horn  of  an  anvil  and  enlarge  bj  hammer- 
ing; if  too  large,  band  the  root  in  the  same  manner  as  for  a  Rich- 
mond crown,  grinding  the  tooth  to  fit. 

TO    INSERT    A    PORCELAIN    FACING. 

Make  the  gold  crown  as  described.  Select  a  porcelain  facing 
suitable  for  the  case  (Fig.  565).  Place  the  crown  on  the  root 
in  the  month,  and  with  an  excavator  mark  on  the  face  where 


Fig.  565. 


Fig.  568. 


Fig.  567. 


Fig.  572. 


Fig.  573. 


Fig.  574. 


the  porcelain  is  to  appear.  Remove  the  crown  and  saw  out,  so 
that  the  facing  will  fit  loosely.  With  a  knife  bevel  the  inner 
edge  or  seat  for  the  facing  (Fig.  566).  Grind  the  facing  to 
fit  (Fig.  567).  Back  up  the  facing  with  !N^o.  34  or  36  gauge  pure 
gold,  punching  holes  in  the  backing  for  pins,  annealing  as  re- 
quired to  readily  conform  it  to  the  tooth  (Figs.  568  and  569). 
With  a  sharp  knife  cut  a  barb  on  each  side  of  the  pins  in  the 
facing,  and  press  the  barbs  against  the  backing  (Fig.  570),  which 
keeps  the  backing  in  place.  Burnish  down  the  edges  well,  being 
careful  not  to  let  the  backing  overlap  the  facing. 

Place  the  facing  in  the  space  prepared  for  it  in  the  crown  (Fig. 
571),  and  bind  the  two  together  (not  too  tight)  with  wire,  wrap- 
ping the  wire  directly  over  the  facing  with  asbestos  to  prevent 


294  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

discoloration  of  the  porcelain,     Flux  and  solder  by  holding  over  a 
lamp  as  in  case  of  a  band  (Fig.  572).     Finish  in  the  usual  way. 

If  it  is  desired  to  use  a  platinum  pin  for  anchorage,  as,  for 
instance,  a  Logan  pin,  bend  the  pins  in  the  facing  sufficiently  to 
clamp  the  anchorage  pin,  and  insert  the  pin  through  the  gold 
crown  (Fig.  573),  finishing  as  before  described.  Fig.  574  shows 
a  finished  crown  so  made. 

TO    MAKE    THE    GRI NDING-SURFACE    OF   A    BRIDGE    IN    ONE 
CONTINUOUS    PIECE. 

After  having  crowned  the  teeth  for  the  attachment  of  the 
bridge,  take  a  bite  in  modelling  compound,  remove  the  com- 
pound, place  the  crowns  in  their  impressions,  make  a  cast  of 

Fig.  575. 


sand  and  plaster,  and  place  on  an  articulator;  now  put  moldine 
between  the  abutments  instead  of  wax,  and  get  the  articulation 
with  cusp-buttons  the  same  as  you  would  for  plate  teeth  (Fig. 
575).  Then,  to  remove  the  buttons  without  destroying  the  articu- 
lation, make  a  cup  by  pouring  Melotte's  metal,  as  cool  as  it  will 
flow,  on  the  face  of  the  cusp-buttons.  Heat  the  pouring  lip  of  the 
ladle  and  use  it  to  smooth  out  the  half -congealed  metal,  much  as 
you  would  a  soldering  iron  (Fig.  576).  Then  place  a  thin  coating 
of  moldine  upon  the  molding  plate.  Remove  the  cup  from  the 
articulator  with  the  cusp-buttons  in  place  (Fig.  576,  a).  Transfer 
the  cusps  by  inverting  the  molding  plate  (Fig.  577),  and  turn  the 
cusp-buttons  out  upon  the  moldine  on  the  plate  with  the  grind- 
ing-surface  up  (Fig.  577,  a),  and  they  will  occupy  the  same  rela- 
tive positions  as  when  on  the  articulator. 

!N"ow  place  the  large  rubber  ring  around  the  buttons  on  the 
plate,  and  proceed  to  make  a  die  with  Melotte's  metal,  as  before 
described  (Fig.  578).  When  cool,  remove  the  buttons  and  coat 
the  face  of  the  die  with  whiting.     Invert  the  die  and  raise  the 


77//';  IIOIJJNaSWOIlTlI  SYSTEM. 


295 


rubber  ring  sufficiently  high  on  it,  and  make  a  counter-die  with 
the  same  metal  by  pouring  as  cool  as  possible  (Fig,  579).  This 
gives  the  male  and  female  dies  with  which  to  swage  the  con- 
tinuous grinding-surfaces.  Then  proceed  to  swage  the  gold  plate 
in  one  piece  (Fig.  580),  annealing  as  often  as  necessary.     Trim 

Fi(i.  57G. 


off  the  surplus  plate  (Fig.  580,  a),  and  place  in  position  on  the 
articulator.  Cut  the  cusps  out  on  the  buccal  face  to  avoid  show- 
ing the  gold  (Fig.  581),  grind  the  porcelain  facings  to  fit  the 
cusps,  and  back  with  gold,  ITo.  34  or  36,  letting  the  gold  come  to 
the  cutting-edge,  the  same  as  in  a  single  crown,  as  before  described. 
If  there  is  a  space  between  the  cutting-edge  and  the  porcelain, 
place  a  little  wax  in  the  joint  to  keep  out  the  plaster  invest- 
ment, invest,  remove  the  wax  from  between  the  joints,  flux,  and 
solder. 

FACINGS    FOR    MAKING    ALL-GOLD    BRIDGE. 

If  it  is  desired  to  make  an  all-gold  bridge,  select  the  proper 
facings  from  the  set,  make  a  die  of  Melotte's  metal,  and  swage 
up,  the  same  as  in  the  continuous  bridge  before  described,  and 
mount  gold  facings  in  place  of  porcelain. 


CHAPTER    XVII. 

CEOWN-  AND  BRIDGE-WOKK  COMBINED  WITH  OPEEATIVE 
DENTISTRY  IN  DENTAL  PROSTHESIS. 


In  croAvn-  and  bridge-work,  artistic  skill  on  the  part  of  the 
operator  can  frequently  be  most  advantageously  displayed  in  the 
conduct  of  operations.  An  appearance  of  symmetry  should  as 
much  as  possible  be  imparted  to  the  upper  front  teeth.  The 
contour  of  the  arch,  the  labial  aspect  and  length  of  the  teeth, 
singly  and  collectively,  on  one  side  of  the  mouth  in  comparison  to 
those  on  the  other,  should  be  observed  and  studied.  That  most 
appreciable  results  are  thus  possible  of  attainment  is  demonstrated 
in  the  following  two  cases : 

In  the  case  presented  in  Fig.  582,  that  of  a  gentleman  of 
about  sixty-two  years  of  age,  is  to  be  seen  the  irregularity  of 

Fig.  582. 


the  teeth  present  and  the  unevenness  of  their  incisive  edges 
and  occluding  surfaces,  the  condition  having  arisen  from  the 
combined  effects  of  decay,  erosion,  mechanical  abrasion,  and  mal- 
occlusion. The  operations  performed  were  as  follows:  On  the 
right  side  the  second  molar  was  restored  by  filling;  the  first 
molar  and  the  bicuspid  crowned  with  gold;  the  cuspid  and  cen- 
tral were  lengthened  with  solid  gold  tips,  each  tip  being  an- 
296 


Ol'ERATIVK  DKNTISTRV   WITH  C'liOWX-  AND  BJtlDdE-WOJiK.    997 

chored  with  three  pins;  and  the  lateral  was  crowned — at  the 
request  of  the  patient — with  gold.  On  the  left  side  the  central 
was  crowned  with  a  gold  crown  with  porcelain  front,  the  cuspid 
shortened  and  filled  on  the  palatal  side,  and  the  bicuspid  crowned 
with  gold  and  the  spaces  bridged. 

Guided  bj  a  line  at  right  angles  to  the  median  line  (Figs.  582 
and  583),  the  teeth  and  crowns  on  one  side  were  formed  to  cor- 
respond as  much  as  possible  in  length,  shape,  and  appearance  to 
those  on  the  other.  Those  teeth  affected  with  pyorrhea  were 
treated.  The  results  of  these  combined  operations,  conducted 
with  a  view  to  the  artistic  as  well  as  the  restorative  effect,  are 
plainly  to  be  seen  in  the  finished  case  illustrated  in  Fig.  583. 

Fig.  583. 


What  can  be  quickly  accomplished  by  judicious  trimming  and 
shaping  of  the  teeth,  in  combination  with  other  operations,  is 
well  illustrated  in  the  following  case:  The  patient's  upper  front 
teeth  presented  the  appearance  shown  in  Fig.  584.  The  right 
central  and  left  lateral  were  pulpless.  The  central  was  badly 
discolored  and  the  lateral  slightly  so.  The  central  had  been 
bleached,  but  in  a  few  years  gradually  resumed  its  former  appear- 
ance. The  other  teeth  with  living  pulps  and  light  in  color  con- 
trasted most  unfavorably.  The  incisive  edges  of  the  centrals  were 
affected  with  atrophy.  The  laterals,  especially  the  right  one,  were 
elongated  from  pyorrhea. i  The  length  of  the  incisors  contrasted 
unfavorably  with  the  cuspids.  The  patient,  a  lady,  was  so  an- 
noyed at  the  appearance  of  the  teeth,  which  she  considered  a 
permanent  disfigurement,  that  she  had  positively  decided  to  have 
all  the  incisors  crowned  or  extracted  and  artificially  replaced.  A 
most  satisfactory  compromise  was  effected,  enaljling  the  patient  to 


298  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

avoid  either  of  these  extreme  measures  by  tlie  performance  of  the 
following  operations:  The  pyorrhea  was  treated,  the  left  lateral 
was  bleached  and  refilled,  the  right  central  natural  crown  excised 
and  an  artificial  one  (style  described  on  page  113)  inserted,  and 
the  atrophied  incisive  edge  of  the  left  central  removed,  all  the 
incisive  ends  of  the  other  teeth  being  trimmed  to  properly  corre- 
spond in  length  and  shape.  The  improvement  effected  is  ap- 
parent in  the  illustration  of  the  finished  case,  Fig.  585. 

Fig.  584. 


V 


Fig.  585. 


The  results  in  dental  prosthesis  which  can  be  accomplished 
by  a  combination  of  operations  on  the  natural  teeth  with  crown- 
and  bridge-work  commend  the  plan  strongly  to  the  experienced 
practitioner.     A  few  more  cases  are  adduced  in  illustration. 

A  case  which  was  interesting,  owing  to  the  conditions  pre- 
sented and  the  various  operations  connected  with  it,  is  illustrated 
in  Fig.  586.  Tig.  587  shows  the  methods  and  operations  prac- 
ticed, and  Fig.  588  the  case  completed. 

The  upper  front  teeth  show  the  effects  of  abrasion  on  the  in- 
cisive edges  and  occluding  surfaces.  The  bicuspids  and  molars 
were  affected  with  pyorrhea  alveolaris.  The  four  incisors  and 
the  left  cuspid  were  pulpless,  and  alveolar  abscess  existed  at  the 
roots  of  three  of  the  incisors.  The  abscesses  and  root-canals  were 
properly  treated.     Gold  collar  crowns  with  porcelain  fronts,  hav- 


OPERA  TIVE  DENTISTR  V  WITJI  CliO  WN-  AND  BRIDGE-  WORK.     299 

ing  flat  incisive  edges  wliicli  perfectly  protected  the  porcelain 
fronts  and  slightly  opened  the  bite,  were  made  for  the  incisors  and 
left  cnspid  (Fig.  587).     The  bicuspids  and  molars  were  placed 


Fig.  586. 


in  as  hygienic  a  condition  as  possible  by  treatment.  On  the 
left  side  a  dummy  bicuspid  with  a  bar  which  fitted  in  a  slot  formed 
to  receive  it  in  the  occluding  surface  of  the  second  bicuspid  was 
attached  to  the  cuspid  crown.  When  the  cuspid  crown  with 
the  dummy  bicuspid  was  cemented  in  position,  the  bar  was  an- 


300 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


chored  in  the  slot  in  tlie  second  bicuspid  with  amalgam.  The 
cuspid  root  being  very  firm,  stability  was  thus  imparted  to  the 
natural  bicuspid,  which  was  quite  loose  because  of  absorption  of 
its  socket.  On  the  right  side  the  second  bicuspid  was  entirely 
capped  with  a  gold  seamless  crown.  On  the  anterior  side  of  this 
gold  crown  an  artificial  tooth  was  attached  as  a  dummy  first  bi- 
cuspid, with  a  bar  extending  from  its  anterior  side  and  fitted 
into  a  slot  formed  in  the  incisive  surface  of  the  natural  cuspid 
crown.  From  the  posterior  side  of  the  second  bicuspid  gold 
crown  a  bar  was  extended  backward  into  the  side  of  the  molar. 
When  the  gold  crown  was  cemented  in  position  on  the  second 
bicuspid,  the  anterior  bar  was  firmly  anchored  in  the  cuspid  with 
a  gold  filling,  which  also  lengthened  the  incisive  edge,  and  the 
posterior  bar  was  fixed  in  the  molar  with  amalgam.  The  reasons 
for  this  form  of  construction  were :  The  second  bicuspid  was  very 

Tig.  588. 


loose  in  its  socket,  and  the  molar,  though  comparatively  more 
stable,  was  also  similarly  affected.  The  attachment  of  the  bar 
in  the  cuspid  supported  the  dummy  bicuspid  and  steadied  the 
second  bicuspid,  and  the  extension  of  the  posterior  bar  into  the 
molar  likewise  afforded  additional  support  to  the  bicuspid.  The 
pulp  of  the  molar  being  exposed,  was  devitalized,  removed,  and 
the  canal  properly  filled.     Fig.  588  shows  the  completed  case.^ 

1  During  the  presence  of  the  patient  in  the  writer's  office,  four  years  after  the 
worlv  was  completed,  the  operations  were  examined  by  members  of  the  profession. 


OPERATIVE  DKNTlSTRy  WITH  CROWN-  AND  BRIDGE-WOJtK.      3OI 


The  lower  teeth,  in  comparison  with  the  upper,  were  but  slightly 
abraded.  The  cuspids  and  one  of  the  incisors  were  tipped  with 
gold.  The  molars  on  the  left  side  were  absent,  so  that  bridge- 
work  on  the  upper  jaw  on  that  side  between  the  bicuspid  and 
molar  would  have  been  to  no  purpose. 

In  the  case  presented  in  Fig.  589  the  operative  procedures  were 
confined  to  the  upper  jaw,  the  lower  teeth  of  the  patient  being 
in  good  condition.  The  bicuspids  and  the  first  and  second  molars 
of  both  sides  of  the  upper  jaw  had  been  lost  many  years  before, 
and  the  incisors  and  cuspids  showed  the  effects  of  extensive  abra- 
sion.    The  occlusion  was  sustained  and  the  principal  part  of  mas- 

FiG.  589. 


tication  performed  by  the  incisors,  as  the  third  molars  had  been 
forced  backward  and  antagonized  only  very  slightly  on  one  side. 
The  patient,  a  gentleman,  had  had  a  plate  inserted,  to  the  pres- 
ence of  which  he  had  vainly  endeavored  to  accustom  his  mouth. 
The  abrasion  of  the  incisors  and  cuspids  was  of  the  rapidly  pro- 
gressive character.  These  teeth,  were  contoured  with  gold  foil  to 
the  form  shown  in  Fig.  591,  and  a  wire  post  was  inserted  in  the 
right  lateral,  which  was  pulpless.     At  the  occluding  section  of 

and  pronounced  apparently  in  as  perfect  condition  as  when  lirst  completed.  The 
treatment  of  the  teeth  affected  with  pyorrhea  and  the  support  imparted  to  them 
by  their  attachment  to  the  other  firm  teeth  and  to  one  another  had  apparently 
checked  the  disease,  and  the  affected  teeth  appeared  to  he  more  secure  in  their 
sockets  than  before  the  insertion  of  the  bridge-work  and  crowns. 


302 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


each  filling,  the  layer  of  gold,  after  being  packed  with  the  plugger, 
was  additionally  condensed  and  hardened  with  a  Herbst  agate- 
point  burnisher  to  enable  it  to  better  resist  the  aggressive  force 
of  the  lower  teeth.  The  third  molars  were  capped  and  length-, 
ened  with  gold  crowns,  the  lines  of  their  sides  being  made  parallel, 
to  admit  of  a  proper  adjustment  of  the  supporting  collars  for  a 

Fig    590 


removable  plate  bridge,  by  adding  gold  on  their  external  sur- 
faces. The  plate  bridge  was  employed  because  of  the  space  be- 
tween the  abutments,  which  suggested  the  idea  of  utilizing  the 
alveolus  to  assist  in  supporting  it.  A  narrow  shoulder  was  formed 
on  each  crown  to  support  the  collars.  The  attachments  to-  the 
cuspids  rested  by  means  of  a  little  shoulder  on  the  occluding 


OPERA  Tl  VK  DENTISTIi  i '  WITH  (JRO  WN-  A  ND  BRID<n^:-  WO  UK.    303 

portions  of  the  fillings  inserted.     Fig.  590  shows  the  completed 
denture,  and  Fig.  591  an  anterior  view  of  the  same.-^ 

In  the  case  illustrated  in  Fig.  592,  the  patient,  a  lady,  had 
previously  worn  a  plate,  the  clasp  of  which  had  entirely  abraded 
the  sides  and  cervix  of  the  right  cuspid  of  enamel,  and  caused 
recession  of  the  margin  of  the  investing  gum.  The  decay  which 
followed  the  abrasion  extended  in  a  circle  around  the  tooth.  As 
the  patient  objected  to  crowns  of  any  kind  being  applied  to  either 
of  the  cuspids,  the  decay  was  removed  and  the  edges  of  the  cavity 
given  a  retaining  form.  A  gold  filling  was  then  introduced  in 
three  sections,  two  of  which  embraced  the  approximal  and  palatal 

Fig.  692. 


sides,  while  the  third  surrounded  the  labial  wall,  joining  the  other 
two  sections  at  that  point,  the  three  thus  completely  encircling 
the  tooth  with  gold.  A  portion  of  the  filling  was  brought  over  the 
edges  of  the  cavity  to  better  shape  the  tooth  for  the  attachment  to 
be  applied,  and  also  to  protect  the  sides  from  future  injury.  When 
this  operation  was  completed,  the  tooth  presented  very  much  the 
appearance  of  having  had  a  close-fitting  shell  crown  applied. 
Gold  fillings  were  introduced  in  the  palatal  and  approximal  sur- 
faces of  the  left  cuspid,  to  protect  it  from  the  attachment.  Gold 
crowns  were  placed  upon  the  molars,  one  of  which,  the  left,  was 
pulpless.  The  appearance  of  the  teeth  after  these  operations  is 
shown  in  Fig.  593. 

^  Case  operated  on  in  1888. 


304 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


A  plate  bridge  (Fig.  594)  was  then  constructed,  the  attachments 
for  which  were  collars  on  the  molars,  and  half-collars  or  clasps 


Fig.   593. 


Fig.  594. 


on  the  cuspids.     The  former  rested  on  shoulders  formed  on  the 
gold  crowns,  and  the  latter  on  the  palatal  curves  of  the  cuspids. 

Fig.  595. 


Fig.   595  illustrates  a  case  as  presented  for  treatment  to  Dr. 
H.  A.  Parr.     The  loss  of  the  posterior  teeth  of  the  lower  jaw 


OI'KRATIVK  DENTISTRY  WITH  CllOWN- AND  BRIDGE-WORK. 


305 


and  the  abrasion  of  the  anterior  teeth  had  resulted  in  the  ab- 
normal occlusion  shown.  The  incisive  edges  of  the  lower  teeth 
were  lengthened  with  gold  contour  fillings.  Gold  collar  crowns 
with  porcelain  fronts  were  placed  on  the  upper  anterior  teeth,  to 
lengthen  them  sufficiently  to  restore  the  occlusion.     The  upper 


molars,  which  were  all  more  or  less  decayed  and  broken  down,  were 
restored  in  form  with  gold  crowns.  The  space  representing  the 
loss  of  the  left  bicuspid  was  filled  with  a  bridge  tooth  having  a 
jjorcelain  front,  attached  to  the  approximal  gold  crown.  In  the 
lower  jaw  a  partial  set  was  inserted  on  each  side  to  substitute  the 
lost  posterior  teeth.  Fig.  596  shows  the  appearance  of  the  case 
when  completed. 


21 


PAKT   lY. 


PORCELAIN  DENTAL  ART. 


POKCELAIN  DENTAL  ART. 

By  porcelain  dental  art  is  here  meant,  not  the  well-known  pro- 
cesses by  which  porcelain  teeth  bought  from  the  manufacturer 
are  mounted  on  metal  or  vulcanite  base,  but  the  actual  working 
of  the  material  porcelain,  from  the  mixing  of  body  and  colors  to 
the  final  baking.  It  involves  the  making  by  the  dentist  of  partial 
crowns  (including  inlays),  entire  crowns,  and  even  bridges,  of 
porcelain.  It  is,  in  some  degree,  a  return  to  the  old  vogue,  when 
the  dentist  made  the  porcelain  teeth  which  he  mounted  for  his 
patients;  but  the  present  practice  is  upon  a  much  higher  plane, 
in  which  the  artistic  is  one  of  the  principal  features. 

Porcelain  dental  art,  as  here  defined,  is  an  outgrowth  largely  of 
the  common  adoption  during  late  years  of  modern  methods  of 
crown-  and  bridge-work.  At  first,  its  possibilities  not  being  clearly 
seen,  its  application  was  confined  to  a  limited  field,  its  sphere  of 
usefulness  widening  as  the  processes  became  better  understood  and 
improvement  after  improvement  was  brought  out.  Recent  meth- 
ods in  the  manipulation  of  porcelain  leave  little  to  be  desired  in 
special  operations,  so  far  as  artistic  merit  and  real  value  are  con- 
cerned. ISTor  can  the  permanency  of  these  operations  be  doubted. 
They  are  no  longer  to  be  classed  as  experimental.  They  have 
been  accepted  as  having  a  legitimate  place  in  dental  prosthesis. 
It  is  by  no  means  intended  to  be  suggested  that  the  processes  in- 
volved in  porcelain  dental  art  have  been  finally  perfected.  Im- 
provements are  quite  possible,  and  may  be  expected  as  more  and 
more  attention  is  attracted  to  this  desirable  field  of  work. 

The  successful  practice  of  porcelain  dental  art  is  not  easy,  as 
will  be  speedily  appreciated  by  those  who  enter  upon  it.  There 
is  demanded  a  technical  and  manipulative  skill  and  a  judgment 
equal  in  degree  to  those  required  in  any  other  class  of  dental 
operations,  a  fact  which  will  serve  only  to  stimulate  the  attainment 
of  perfection  in  its  methods. 

In  presenting  the  subject  we  shall  deal  first  with  porcelain  in- 
lays, a  department  which  has  come  into  especial  prominence  within 
the  past  few  years. 

309 


CHAPTER   I. 

POKCELAIlSr  INLAYS. 

The  Earlier  Methods. — The  first  operations  in  porcelain  inlays 
or  fillings  consisted  in  shaping  pieces  of  porcelain  as  nearly  as 
might  be  to  the  form  of  the  prepared  cavity,  into  which  they  were 
then  cemented.  These  inlays  were  cut  from  porcelain  teeth,  which 
were  selected  to  match  the  natural  teeth  into  which  the  inlays 
were  to  be  inserted.  Various  forms  of  inlays  were  then  put  upon 
the  market  by  the  manufacturers  to  meet  the  needs  of  this  class 
of  work,  which,  however,  never  attained  any  special  prominence. 
A  little  later,  slightly  tapering  round  rods  of  porcelain  were  sup- 
plied for  filling  labial  cavities  in  front  teeth.  The  cavity  was 
made  perfectly  round,  to  fit  the  end  of  a  rod  corresponding  in 
size,  which  was  fitted  tightly,  cut  off,  cemented  in  place,  and 
when  the  cement  had  set  was  trimmed  evenly  with  the  surface  of 
the  enamel  of  the  tooth.  Both  methods  are  still  employed  to  a 
limited  extent,  the  last-named  being  especially  adapted  to  small 
cavities  on  the  labial  surfaces. 

Then  we  had  glass  inlays,  of  which  a  number  were  brought  be- 
fore the  profession,  but  they  failed  to  show  the  permanent  value 
requisite,  mainly  because  the  inlays,  besides  lacking  the  necessary 
strength,  showed  a  decided  tendency  to  discolor  in  actual  service. 
They  were,  nevertheless,  an  important  step  in  the  progression 
which  led  up  to  the  modern  porcelain  inlay. 

Modern  Inlays. — The  porcelain  inlay  as  now  used  is  a  dental 
porcelain  fused  in  a  carefully  made  matrix  of  the  cavity  to  be 
filled,  of  the  exact  form  and  size  required.  Two  general  grades 
of  porcelain  are  in  use  for  inlay  work,  made  respectively  from 
"High-Fusing  Body"  and  "Low-Fusing  Body." 

A  high-fusing  body  is  one  which  does  not  fuse  until  a  tempera- 
ture above  the  melting  point  of  gold  is  reached;  and  which  con- 
310 


POR  CELAIN  I  NLA  VS.  ^n 

seqnently  requires  that  the  matrix  in  which  the  inlay  is  formed 
shall  be  of  platinum.  In  some  operations  the  body  used  requires 
as  high  a  temperature  as  the  fusing  of  the  ordinary  porcelain 
teeth. 

A  low-fusing  body,  on  the  contrary,  is  one  which  fuses  before 
the  melting  point  of  gold  is  reached.  The  "Jenkins"  body,  for 
instances,  fuses  at  at  least  100  degrees  of  Fahrenheit  below  it. 
For  low-fusing  bodies,  gold,  which  is  a  more  tractable  metal  than 
platinum,  is  used  for  the  matrix. 

The  respective  merits  of  high-  and  low-fusing  porcelains  for  in- 
lay work  have  been  much  discussed,  and  wide  differences  of  opinion 
prevail  concerning  them.  The  characteristics  of  both  and  the 
methods  of  manipulation  and  their  application  to  various  opera- 
tions will  be  impartially  presented. 

A  properly  made  and  inserted  porcelain  inlay  affords  the  very 
decided  advantage  of  restoring  lost  tooth-structure  not  only  in 
substance,  but  in  appearance.  Porcelain  inlays  are  used  princi- 
pally on  the  labial,  buccal,  and  approximal  surfaces  of  teeth  from 
bicuspid  to  bicuspid.  They  are  also  used  on  the  occlusal  sur- 
faces of  bicuspids  and  upon  the  anterior  approximal  sides  of  molars 
where  the  tooth  immediately  in  front  is  missing.  They  add 
strength  to  a  frail  tooth  and  prevent  thermal  shock  in  sensitive 
cavities. 

The  first  requirement  in  a  porcelain  inlay  is  that  it  shall  ac- 
curately conform  to  the  shape  of  the  cavity,  with  an  absolute  fit 
of  the  orifice  or  of  the  orifice  and  side  walls.  The  base  of  the 
inlay  rests  on  the  center  of  the  bottom  of  the  cavity.  The  cement 
with  which  it  is  luted  fills  in  all  parts  of  the  cavity  not  occupied 
by  the  porcelain,  including  deep  recesses  and  undercuts.  The  in- 
lay is  consequently  held  in  position  by  the  adhesion  of  the  cement. 

PREPARATION  OF  CAVITIES. 

Cavities  for  porcelain  inlays  are  to  be  excavated  more  as  for  plas- 
tic work  than  for  gold,  and  without  undercuts.  The  effort  should 
be  to  give  a  cup-shaped  formation  with  the  orifice  a  little  larger 
than  the  bottom,  so  that  the  matrix  of  gold  or  platinum  when 
adapted  to  the  cavity  can  be  removed  without  disturbing  its  shape. 
This  ideal  form  is  not  to  be  obtained  by  excessive  removal  of  the 
walls  or  enamel.     Unnecessary  cutting  away  of  tooth-substance  is 


312 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


to  be  avoided.  When  the  decay  has  proceeded  in  such  wise  as  to 
form  deep  recesses,  it  is  not  desirable  nor  necessary  to  cut  away 
the  tooth  to  make  the  ideal  cavity  form  include  them.  After  re- 
moving the  carious  portions  from  such  recesses,  they  can  be  filled 
with  cement  so  that  the  cup-shaped  form  for  the  matrix  shall  in- 
clude only  the  main  cavity,  the  cement  where  it  joins  the  main 
cavity  being  dressed  to  conform  to  the  proper  contour.  The  ex- 
ception to  this  rule  is  where  a  bar  or  horn-like  formation  of  the 
porcelain  is  made  at  some  point  as  an  anchorage  to  an  inlay  which 
involves  restoration  of  the  contour  of  the  working  surface  of 
the  tooth,  as  of  an  incisor  edge.  The  orifice  of  the  cavity  should 
be  given  an  oval  or  oblong  form  with  one  end  or  side  differing 

Fig.  697. 


I 


somewhat  in  shape  from  the  others,  to  define  the  exact  position 
the  inlay  is  to  occupy  when  inserted  in  the  cavity.  The  margins 
should  be  trimmed  evenly  and  the  side  walls  inclined  at  nearly  a 
right  angle  to  the  line  of  the  enamel  surface,  especially  at  a  point 
where  the  force  of  mastication  is  to  be  withstood.  The  surround- 
ing edge  of  the  enamel  should  be  sharp  and  well  defined.  It  is 
well  to  polish  around  the  margins  inside  the  cavity  with  soft  iron 
burs,  charged  with  diamond  dust,  kept  wet  during  the  polishing. 
A  set  of  forms  such  as  are  illustrated  in  Fig.  597  are  suitable  for 
the  purpose.  The  use  of  sand-paper  disks  or  strips  across  the  sur- 
face of  the  enamel  should  be  avoided,  as  it  is  apt  to  make  a  coarse 
joint. 

Figs.  598,  599,  600,  and  601  illustrate  teeth  with  prepared 
cavities  and  their  inlays  of  the  classes  commonly  involved  in  the 
practice  of  porcelain  work. 

Fig.  602  outlines,  in  section,  the  preparation  of  an  ordinary 


PORCELAIN  INLAYS. 
Fig.  698. 


313 


Fig.  599. 


Fig.  600. 


Fig.  601. 


cervical  cavity.  The  line  A  A  repre- 
sents tlie  prepared  cavity.  B  B,  the 
point  where  an  undercut  may  be  made 
when  the  porcelain  is  ready  for  inser- 
tion, C  C,  the  gold  or  platinum 
matrix.  Such  cavities  require  to  be 
moderately  deep,  in  order  that  the 
inlay  shall  be  of  sufficient  thickness 
to  overcome  the  effect  of  the  cement, 
which  would  otherwise  modify  the 
shade  owing  to  the  translucency  of 
the  porcelain.  A  cavity  of  this  char- 
acter, if  not  located  very  close  to  the 


Fig.  602, 


314 


.1  RTIFICL 1  L  CRO  WX-  A  XP  BRIPaF-  ]yORK. 


Fig.  603. 


methods. 


giiiu-inargiii,  being  one  of  the  most  simple,  is  generally  the  best 
to  begin  practical  work  on. 

Fig.  G03  represents  a  tvpical  c^ivity  in  the  approximal  side  of 
an  incisor.  The  dark  portion.  A,  in  the  sectional  view,  represents 
a  recess  in  tlie  cavity  made  necessary  by  extension 
uf  the  decay  in  that  diix^ction,  which  recess  must  be 
tilled  with  cement  to  give  proper  form  to  the  matrix. 
In  tJie  case  of  approximal  ea^^.ties,  ample  space  is  re- 
quired for  the  proper  manipulation  of  the  matrix  and 
the  insertion  of  the  porcelain  tilling.  The  necessary 
room  must  be  obtained  by  preparatory  wedging  or 
by  the  use  of  a  separator,  or  by  combining  both 
Theiv  must  be  sut^cient  space  to  permit  the  matrix, 
after  it  has  been  perfectly  conformed  to  the  cavity,  to  be  lifted 
cut  witJiout  disturbing  its  form  ii\  the  least,  and  also  to  allow 
the  porcelain  to  be  freely  inserted. 

In  tlie  upper  incisors,  when  a  portion  of  the  palatal  wall  can 
properly  be  romoved,  as  shown  at  A,  Tig.  509,  less  space  is  re- 
quirod.  and  removal  of  tlie  matrix  and  insertion  of  the  inlay 
are  considerably  facilitated.  Cavities  in  bicuspids  and  molars, 
such  as  ai*e  illustrated  in  Figs.  600  and  601,  involving  the  ap- 
proximal and  grinding  surfaces,  usually  permit  the  matrix  to  be 
more  easily  removed  than  when  only  an  approximal  surface  is 
involved. 

TO  FORM   THE  MATRIX. 

Kolled  gold  foil  No.  30, — for  large  cavities  Js^o.  -iO  is  used, — 
or  platinum  foil  l-:2000  to  l-lOOO  of  an  inch  in  thickness  is  used. 
To  render  the  platinum  soft  enough  for  the  purpose,  it  should 
be  previously  annealed  at  a  white  heat  in  the  mutHe  of  a  gas 
furnace,  or,  preferably,  on  a  piece  of  lime  in  an  electric  furnace. 
Annealed  by  the  latter  method  it  becomes  nearly  as  soft  and 
pliable  as  gold.  A  diroct  gas  flame  is  not  suitable,  as  the  desired 
softness  cannot  be  obtained  by  tliat  me^iis.  The  foil  should  be  cut 
large  enough  to  cover  the  walls  of  the  cavity  and  extend  over  the 
adjacent  surface  of  the  enamel  one-eighth  of  an  inch,  more  or  less, 
according  to  the  position,  character,  and  size  of  the  cavity.  The 
surplus  foil,  when  sliaped  to  the  contour  of  the  tooth  around  the 
cavity,  serves  to  outline  the  contour  to  be  given  the  inlay  when  the 
porcelain  body  is  inserted  in  the  matrix.     The  foil  is  placed  over 


PORCELA  IX  I  NLA  VS. 


315 


the  cavity,  the  edges 
of  which  are  defined,  | 
'and  is  first  brought 
gently  down  into  the 
center  of  cavity  with 
a  bit  of  spunk  or  a 
pellet  of  cotton  held 
in  foil-tweezers,  or 
when  necessary  by  a 
ball  burnisher,  as  ISTo. 
1  of  the  set  illustrated 
in  Fig.  604,  and  then 
against  the  walls.  Re- 
move the  spunk,  see  if 
the  adjustment  of  the 
foil  to  the  cavity  is 
satisfactory,  then  re- 
place the  spunk,  hold- 
ing it  in  place  with 
the  left  hand,  by 
pressing  in  the  center 
with  a  ball  burnisher. 
ISText,  with  another 
piece  of  spunk  held  in 
tweezers  in  the  right 
hand,  bring  down  the 
foil  over  the  edges 
and  on  the  surface  of 
the  enamel  around 
the  cavity,  and  bur- 
nish it  with  a  bur- 
nisher, such  as  is 
shown  in  No.  2,  Fig. 
604.  In  the  adapta- 
tion of  the  foil  to  the 
cavity,  and  especially 
for  holding  it  in  posi- 
tion    in    the    center 


316  AR TIFICIAL  CRO  WN-  AND  BRIDGE-  WORK. 

^vhile  the  marginal  section  is  being  manipulatedj  the  author 
has  found  that  a  wisp  of  cotton,  twisted  around  an  old-fash- 
ioned, long-handled  cavity  bur,  is  very  serviceable.  The  foil^ 
whether  gold  or  platinum,  may  be  removed  and  again  annealed, 
after  being  shaped  to  the  bottom  of  the  cavity,  and  before  it  is 
shaped  to  the  sides.  Thorough  burnishing  of  the  sides  and  mar- 
gins of  the  matrix  should  follow  the  final  annealing  to  impart  the 
greatest  possible  amount  of  rigidity  to  the  foil  before  its  final  re- 
moval. A  little  vaselin  may  be  applied  to  the  surface  of  the  gum, 
enamel,  and  cavity,  to  prevent  adhesion  of  the  foil.  Platinum 
foil,  1-1000-inch,  has  the  advantage  that  it  can  be  burnished  on 
the  surface  of  a  tooth  under  a  gum-margin.  Should  the  foil  tear 
slightly  in  the  center  of  the  cavity,  which  it  is  very  apt  to  do  dur- 
ing adaptation,  it  is  not  a  serious  matter,  as  the  porcelain  body  will 
fill  in  the  aperture,  and  draw  from  the  edge  in  the  first  fusing. 

The  removal  of  the  matrix  requires  most  gentle,  delicate  ma- 
nipulation, as  it  must  be  accomplished  without  the  slightest  altera- 
tion of  the  form.  On  account  of  its  greater  rigidity  platinum 
foil  is  more  easily  removed  than  gold.  The  cavity  will  generally 
have  one  wall  inclined  slightly  more  than  the  remainder;  a  con- 
formation which  is  easily  made.  Deep  in  the  cavity,  at  the  slant- 
ing side,  insert  a  fine  hoe-shaped  instrument  into  the  foil,  and 
loosen  and  gently  coax  it  from  its  position.  When  loosened,  take 
an  edge  of  the  foil  with  tweezers  and  lift  the  matrix  from  the 
cavity. 

The  removal  of  a  matrix  is  much  simplified,  and  alteration  of 
its  form  assured  against,  by  filling  the  cavity  with  wax.  Soften 
and  roll  up  a  pellet  of  hard,  tough  wax,  a  trifle  larger  than  the 
cavity;  introduce  the  pellet  of  wax  into  the  cavity  of  the  matrix 
and  press  it  down  with  a  flat  burnisher  (l^o.  4,  Fig.  604),  covered 
with  pulverized  soapstone  to  prevent  adhesion  of  the  wax  to  the 
instrument.  In  approximal  cavities  the  pressure  is  best  exerted 
with  a  strip  of  tape  covered  with  the  soapstone.  The  pressure 
should  be  steady  and  direct.  The  wax  should  extend  over  the 
edge  of  the  cavity  onto  the  foil,  but  at  no  point  beyond  its  mar- 
gin, as  adhesion  of  the  wax  to  the  tooth  would  interfere  with  re- 
moval of  the  matrix.  A  stream  of  cold  water  from  a  syringe  is 
next  thrown  on  the  wax,  and  the  matrix  is  then  started  and  re- 
moved from  the  cavity. 


PORCELAIN  INLAYS.  317 

To  facilitate  the  shaping  of  either  a  gold  or  a  platinum  foil 
matrix,  the  foil  may  be  placed  on  the  surface  of  a  piece  of  soft, 
fine-grained  cork,  and  with  a  ball-shaped  burnisher  the  center  may 
be  pressed  into  the  cork  and  -given  a  cup-shaped  form  approxi- 
mating that  of  the  cavity.  A  slit  placed  in  the  foil  at  about  the 
point  A,  Fig.  599,  to  be  assumed  by  the  matrix,  has  also  been  sug- 
gested, but  preferably  is  to  be  avoided. 

A  mold  of  the  cavity  has  also  been  used  to  some  extent.  In  the 
case  of  a  cervical  cavity,  the  impression  is  taken  on  the  end  of  a 
cone  of  impression  compound.  For  an  approximal  cavity,  a  small 
piece  of  the  compound  is  fitted  to  the  cavity,  chilled  with  water 
from  a  syringe,  and  withdrawn  or  tipped  out  with  the  point  of  an 
excavator.  A  mold  of  the  cavity  is  then  made  by  again  chilling 
the  impression  with  cold  water  and  pressing  it  against  and  into 
the  surface  of  another  small  piece  of  softened  impression  com- 
pound, chilling  the  compound  and  separating  impression  and  mold. 
Another  method  is  to  make  a  mold  from  the  compound  impression 
in  plaster  and  then  boil  the  plaster  in  stearin  to  toughen  it. 

Oxyphosphate  is  also  used  to  form  the  mold.  The  cavity  and 
surface  of  the  tooth  are  dried  and  dusted  with  soapstone  applied 
with  a  camel's-hair  brush.  A  ball  of  oxyphosphate  mixed  mod- 
erately stiff,  and  kneaded  with  the  fingers,  is  pressed  into  the 
cavity  and  over  the  margins.  When  set,  this  oxyphosphate  im- 
pression or  die  of  the  cavity  is  removed,  and  its  base  inserted  in  the 
surface  of  a  small  mass  of  plaster  and  the  plaster  trimmed  either 
round  or  square,  The  surface  of  the  die  is  next  dusted  with  soap- 
stone  and  a  small  mass  of  oxyphosphate,  mixed  to  a  plastic  con- 
sistence, pressed  over  it.  When  the  oxyphosphate  has  set,  it  is 
separated  from  the  die  and  replaced,  the  surface  of  the  plaster 
oiled,  and  plaster  poured  over  it  sufficient  to  complete  this  section 
of  the  mold.  By  this  method  so  accurate  a  mold  of  the  cavity  is 
obtained  that  it  is  possible  to  shape  a  matrix  and  entirely  form  an 
inlay  without  fitting  in  the  mouth. 

The  first  described  method  is  a  very  practical  one  and  the  work 
is  easily  performed.  The  gold  or  platinum  foil,  after  being  first 
shaped  in  the  mold,  is  then  fitted  to  the  cavity  in  the  tooth. 

INVESTING  THE  MATRIX. 

In  the  use  of  a  1-1000-inch  platinum  foil  matrix,  for  high-fusing 
porcelain,  investment  of  the  matrix  is  not  generally  practiced. 


318  ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 

The  gold  foil  or  tlie  1-2000  platinum  foil  matrix  requires  invest- 
ment, owing  to  the  great  shrinkage  that  occurs,  especially  in  the 
fusing  of  the  first  application  of  the  porcelain  body.  Dr.  Jenkins's 
method  of  investing  a  gold  foil  matrix,  which  may  also  be  used 
for  platinum  foil,  in  connection  with  the  use  of  his  low-fusing 
porcelain,  is  given  below : 

Mix  finely  powdered  asbestos  with  water  to  the  desired  con- 
sistence and  place  in  the  platinum  cup  which  is  included  in  his 
outfit  and  is  illustrated  in  Tig.  605,  suificient  of  it  to  imbed  the 
p^^  g^g  matrix.     Lay  the  gold  foil  matrix  on  the 

surface  of  the  asbestos,  slightly  tap  the 
cup,  and  the  matrix  will  settle  down  in 
place  in  the  asbestos.  Should  some  of  the 
walls  stand  high,  a  little  of  the  asbestos 
should  be  carried  under  them  with  the 
point  of  a  camel's-hair  brush,  or  an  ivory 
spatula,  so  that  the  matrix  is  everywhere 
equally  supported.     Fig.  605  shows  an  invested  matrix. 

When  wax  is  used  in  the  matrix,  to  assist  its  removal  the  matrix 
should  be  invested  the  same  as  for  the  formation  of  a  gold  inlay. 
Take  very  finely  ground  calcined  marble-dust  two  parts,  and  plas- 
ter one  part.  First  thoroughly  mix  them,  and  then  add  enough 
water  to  form  a  moderately  thin  paste;  place  a  proper  quantity 
of  the  investing  material  on  a  piece  of  paper  on  the  bench,  set 
the  matrix  on  the  center  and  let  it  settle  into  the  investment.  A 
few  taps  on  the  bench  alongside,  sufiiciently  hard  to  jar  it,  will 
assist  the  settling.  When  the  investment  has  set,  the  wax  is 
washed  out  with  a  stream  of  boiling  water.  JSText,  dry  and  heat 
over  a  Bunsen  flame  until  the  investment  approaches  a  red  heat, 
then  let  it  cool  and  the  matrix  is  ready  for  the  application  of  the 
porcelain. 

Should  an  invested  matrix  formed  of  gold  or  extremely  thin 
platinum  be  removed  from  its  investment  and  fitted  to  the  cavity 
between  fusings,  it  will  have  to  be  again  invested. 

SELECTING    THE    COLOR    OF    THE    PORCELAIN    BODY. 

The  proper  color  of  porcelain  should  be  selected  from  the  sam- 
ples while  the  tooth  is  wet,  as  dryness  affects  the  shade.  In  ap- 
proximal  cavities  in  the  incisors  it  is  well  to  select  a  color  a  trifle 


PORCELAIN  INLA  YH.  319 

lighter  than  that  of  the  natural  teeth,  as  shadows  and  the  cement, 
owing  to  the  translucency  of  the  porcelain,  have  a  tendency  to 
darken  the  appearance  of  the  inlay.  Should  none  of  the  samples 
properly  correspond  in  color,  it  is  customary  to  mix  different  shades 
of  the  porcelain  body  to  obtain  the  desired  one.  "Whatever  color 
is  required,  first  ascertain  the  basal  color  and  to  this  add  the  toning 
material.  For  instance,  taking  yellow  as  the  basal  color,  a  variety 
of  shades  can  be  formed  by  the  addition  of  white.  Insufficient 
fusing  will  render  the  porcelain  a  trifle  darker  than  the  true  shade, 
and  excessive  heat  will  lighten  it. 

Application  of  the  Porcelain. — The  methods  of  procedure  in 
applying  the  body  with  low-  and  high-fusing  porcelains  are  quite 
similar,  irrespective  of  the  degree  of  heat  required.  A  description 
of  the  use  of  one  style  will,  in  a  measure,  explain  the  subject  for 
both. 

DR.    JENKINS'S    LOW-FUSING    PORCELAIN. 

This  is  a  porcelain  introduced  by  Dr.  IST.  S.  Jenkins,  of  Dresden. 
It  is  compounded  according  to  formulas  and  knowledge  acquired 
of  the  porcelain  workers  of  Dresden.  It  fuses  at  at  least  100 
degrees  of  Fahrenheit  below  the  melting  point  of  gold.  It  forms 
a  dense,  hard  porcelain  with  a  glossy  surface  resembling  in  appear- 
ance the  porcelain  of  the  English  tooth  more  than  that  of  the 
American.  The  following  is  an  explanation  of  the  use  of  the 
Jenkins  porcelain  and  the  appurtenances  connected  with  it:  Place 
upon  the  agate  pallet  with  a  spatula  (see  ISTo.  2,  Fig.  606)  a  small 
quantity  of  the  selected  color  and  mix  it  with  absolute  alcohol. 
With  the  small  thin  blade  of  the  spatula  carry  the  well-moistened 
powder  into  the  matrix,  filling  it  up  but  taking  care  not  to  over- 
flow the  edges.  If,  in  this  packing,  the  powder  gets  too  dry,  either 
in  the  matrix  or  on  the  pallet,  add  more  alcohol  with  the  drop 
tube.  Carefully  avoid  the  introduction  of  foreign  matters  into 
tlie  porcelain  powder.  Put  the  small  cover  on  the  fusing-cup 
with  the  opening  toward  the  handle.  Then  hold  the  cup  across 
the  hole  in  the  heater  and  turn  a  very  fine  flame  from  the  blow- 
pipe onto  the  handle  about  an  inch  from  the  fusing-cup,  thus 
gradually  drying  the  asbestos.  Do  this  without  hurry.  The 
moisture  must  be  evaporated,  not  boiled  out.  IText,  turn  the 
flame  upon  the  bottom  of  the  cup,  slowly  and  gently  increasing 


320 


ARTIFICIAL  CROWN- AND  BRWGE-WORK. 


the  ilame  and  the  draft  from  the  foot-bellows  until  the  porcelain 
enamel  is  fused  (see  Fig.  607).  No  violent  action  of  the  bellows 
is  necessary;  a  small  flame  and  a  little  draft  are  sufficient  in 


Fig.  606. 


Fig.  607. 


most  cases.  It  is  of  no  consequence  if 
the  first  fusing  is  rough  and  irregular. 
The  material  is  not  designed  to  flow 
easily.  When  the  powder  begins  to 
fuse,  hold  the  flame  and  draft  as  it  is, 
and  do  not  try  to  accelerate  the  melting 
by  rapidly  increasing  the  heat.  The 
process  of  fusing  can  be  seen  clearly 
through  the  opening  of  the  platinum 
cover.  The  first  fusing  will  not  be  suf- ' 
ficient,  as  the  powder  contracts  greatly, 
but  the  cover  can  be  at  once  removed 
and  the  cooling  hastened  by  wetting  the  bottom  of  the  cup  with 
water,  as  the  material  is  not  liable  to  crack.  Next  pack  the 
matrix  with  powder  as  before.  Keep  wetting  it  with  alcohol  if  it 
dries  quickly.     It  does  no  harm  if  the  asbestos  becomes  moistened 


PORCELAIN  INLAYS.  321 

with  alcohol,  but  avoid  wetting  it  with  water  after  the  first 
heating.  Turn  a  small  flame,  at  first,  on  the  handle  and  presently 
a  blue  flame  will  appear  at  the  opening  of  the  cover.  Let  the 
alcohol  burn  until  it  is  quite  consumed  and  then  fuse  the  porce- 
lain body  as  before.  Generally  a  third  packing  and  melting  are 
necessary  for  exactness  of  edges  and  contour.  Examine  the  inlay 
with  a  magnifying  glass  to  be  sure  that  the  edges  are  exact,  both 
in  packing  and  after  fusing.  The  tendency  on  the  part  of  the 
operator,  in  the  beginning,  is  to  build  out  too  much,  but  after 
some  experience  he  learns  to  get  exactly  the  form  and  fullness 
desired.  After  the  final  melting  it  is  better  to  let  the  piece  cool 
somewhat  slowly.  This  style  of  porcelain  can  be  baked  in  a  gas 
or  electric  furnace  as  well  as  by  the  process  described  by  Dr. 
Jenkins. 

HIGH-FUSING    PORCELAIN. 

High-fusing  porcelain  involves  the  use  of  a  platinum  matrix, 
as  it  requires  a  very  high  temperature  to  fuse  it.  The  shade  of 
body  selected  as  suitable  is  wet  with  distilled  water  and  dried 
with  blotting-paper  to  the  consistence  of  a  paste.  The  matrix 
may  be  invested  or  not.  If  not  invested  it  is  held  by  the  edge  with 
pliers,  the  body  is  placed  in  it,  and  settled  to  the  bottom  by  a  few 
taps  on  the  pliers.  The  body  should  not  be  allowed  to  come 
quite  up  to  the  edge  of  the  matrix.  The  matrix  is  then  placed  in 
the  furnace,  heated  up  slowly,  and  the  body  baked.  When  not 
invested,  the  matrix  should  be  placed  on  a  bed  of  finely  pulver- 
ized silex  on  a  slab.  The  heat  should  be  sufficient  to  give  tha 
body  a  slight  gloss.  The  first  baking  is  termed  "biscuiting,"  anct 
considerable  shrinkage  takes  place.  The  matrix  is  again  placed 
in  the  cavity,  and  the  edges,  which  are  always  drawn  from  the 
original  form  by  the  contraction  of  the  porcelain,  are  thoroughly 
burnished  to  the  tooth.  The  larger  the  matrix,  the  more  notice- 
able the  shrinkage  will  be.  More  porcelain  body  is  now  placed 
in  the  matrix,  filling  it  to  the  edges,  and  a  second  baking  given. 
A  third  addition  of  body  and  baking  is  generally  necessary.  The 
porcelain,  after  the  final  baking,  should  be  cooled  slowly. 

REMOVING    THE    FOIL    MATRIX. 

When  the  inlay  is  cool,  always  first  wet  it  with  water  before 
handling,  then,  if  invested,  remove  it  from  its  investment.     With. 

22 


322  -^R TIFICIAL  CRO  WN-  AND  BRID GE-  WORK. 

tweezers  gently  and  slowly  bend  back  tlie  foil  from  the  edges  and 
it  will  usually  strip  off  in  one  piece.  If  any  sbreds  of  foil  adhere 
to  the  inlay,  remove  them  with  a  fine  excavator. 

CEMENTATION. 

When  an  inlay  is  ready  to  be  inserted  it  should  be  placed  on  the 
operating  case  in  the  same  relative  position  it  will  take  in  the 
tooth,  or,  the  surface  of  the  tooth  and  of  the  inlay  at  one  side 
of  the  cavity  may  be  given  a  pencil  or  ink  mark.  Such  pre- 
cautions prevent  mistakes  and  instantly  indicate  the  position  the 
inlay  is  to  assume  as  it  is  being  inserted  with  the  cement.  Grooves 
are  to  be  made  in  the  porcelain  with  a  small  diamond  disk  (see 
Eig.  608),  or  the  gloss  removed  for  better  adhesion  of  the  cement. 
When  the  inlay  is  too  small  to  handle  conveniently, 
the  gloss  can  be  removed  by  covering  the  front  and 
edges  with  wax  and  applying  hydrofluoric  acid  for  a 
few  minutes.  A  few  grooves  may  be  made  in  the  walls 
of  the  cavity,  but  this  is  not  considered  necessary  al- 
ways. The  oxyphosphate  cement  should  be  mixed  to 
the  consistence  of  a  thick  cream.  The  inlay  and  cavity 
having  been  dried  perfectly,  a  little  of  the  cement  is 
smeared  in  every  part  of  the  cavity  and  on  the  sides 
and  bottom  of  the  inlay,  and  especially  in  the  grooves. 
The  inlay  is  then  placed  in  the  cavity  and  gradually  pressed  home. 
Before  it  is  quite  in  place,  the  surplus  cement  should  be  removed, 
the  inlay  carefully  examined  to  see  if  it  is  exactly  in  proper  posi- 
tion, and  the  final  pressure  given  with  a  properly  shaped  piece  of 
wood.  The  final  pressure  should  be  gentle  and  elastic,  and  ex- 
erted on  the  center  of  the  inlay,  until  all  surplus  cement  has  oozed 
out.  In  approximal  cavities  a  piece  of  tape  or  floss  silk  can  be 
used  to  press  an  inlay  in  place,  but  a  wedge-shaped  piece  of  wood 
is  to  be  preferred.  If  the  rubber  dam  is  used,  leave  it  on  until  the 
cement  has  set,  but  in  a  case  where  the  dam  is  inapplicable,  paraffin 
should  be  melted  on  or  varnish  painted  over  the  inlay.  At  a  sub- 
sequent sitting,  any  particles  of  oxyphosphate  which  may  be  still 
clinging  to  the  tooth  or  inlay  should  be  removed. 

POINTS  TO   BEAR  IN   MIND. 

In  the  adaptation  of  a  matrix  the  process  is  greatly  simplified 
by  freedom  from  interference  by  the  gum  and  the  presence  of 


PORCELAIN  INLAYS.  323 

abundant  approximal  space.  In  cases  where  cervical  decay  ex- 
tends under  the  gum-margin,  the  cavity  should  be  previously 
packed  with  cotton  or  gutta-peroha,  and  the  gum  pressed  from  nor- 
mal position  sufficiently  to  fully  expose  the  edge  of  the  cavity  and 
admit  perfect  adaptation  of  the  matrix.  The  method  of  packing 
the  cavity  of  the  matrix  with  wax,  in  such  a  case,  is  to  be  recom- 
mended, especially  if  gold  foil  is  used,  as  the  wax  will  maintain 
the  position  of  the  foil  should  any  point  press  against  the  gum. 
This  method,  although  increasing  the  detail  of  the  operation,  com- 
pensates by  simplifying  it  and  assuring  its  successful  performance. 

The  use  of  a  3-inch  lens  magnifying  about  two  diameters, 
mounted  on  a  stand  so  that  the  work  can  be  held  under  it  and 
viewed  at  pleasure,  will  prove  of  great  assistance,  especially  in 
the  manipulation  of  the  porcelain  body  in  the  matrix. 

Small  camel's-hair  artist's  brushes  will  be  found  very  serviceable 
for  brushing  and  removing  particles  of  the  porcelain  body  around 
the  edge  of  the  matrix,  and  at  times  adjusting  small  portions  of  it 
in  proper  position. 

In  the  use  of  any  grade  of  porcelain  the  most  extensive  shrink- 
age occurs  in  the  first  baking.  The  porcelain  contracts  from  the 
sides  toward  the  center.  Dr.  J.  L,  Williams  suggests  that  for  the 
first  baking  the  porcelain  body  be  placed  like  a  ring  around  the 
sides  of  the  matrix,  leaving  the  center  open.  This  gives  a  tend- 
ency to  the  porcelain  to  shrink  from  the  center  toward  the  sides. 

To  cause  the  edges  of  the  inlay  to  fit  very  closely  to  the  margins, 
in  case  of  a  large  cavity,  it  has  been  suggested  that  an  extra  form 
of  foil  be  adapted  to  the  bottom  of  the  cavity,  extending  slightly 
up  on  the  sides,  leaving  some  space  between  the  upper  edge  of  the 
foil  and  the  orifice  of  the  cavity.  Over  this  form  the  regular 
matrix  is  then  adapted.  The  idea  is  that  the  edge  of  the  inlay  will 
approximate  the  margin  of  the  cavity  more  closely  by  the  thick- 
ness of  the  foil  than  it  otherwise  would. 

Few  experts  in  the  formation  of  porcelain  inlays  use  a  die  or 
mold  of  the  cavity  to  assist  in  shaping  the  matrix.  If  time  at  the 
operating  chair  is  to  be  considered,  the  best  plan  in  the  simpler 
operations  of  this  class  is  to  fill  the  matrix  with  wax,  remove  and 
invest  (see  page  317),  then  dismiss  the  patient,  and  have  the  inlay 
formed  by  the  next  appointment. 

In  atrophy  of  the  enamel,  as  illustrated  in  Fig.  609,  porcelain 


324 


ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 


inlay-work  is  specially  suitable.  In  cases  of  erosion,  where  shrink- 
age of  the  gnm  causes  exposure  of  a  portion  of  the  root,  as  shown 
in  Fig.  610,  the  section  of  the  inlay  over  the  root  can  be  enameled 
with  gum-colored  porcelain. 


Fig.  609. 


Fig.  GIO. 


When  considerable  contour  is  given  or  a  corner  is  built  out. 
Fig.  611.  for  instance  in  a  case  such  as  is  represented  in 
Fig.  611,  the  porcelain  should  be  set  at  a  right 
angle  to  the  biting  or  incising  edge  of  the  tooth 
under  treatment,  as  shown  at  A,  or  chipping  is  liable 
to  occur.  In  such  cases  a  projecting  horn  of  the 
porcelain  (B)  will  make  a  much  stronger  anchorage 
than  a  platinum  pin.  A  platinum  pin  in  a  small 
mass  of  porcelain  has  a  tendency  to  weaken  it  by  breaking  up  the 
continuity  of  its  structure. 

In  building  up  corners  of  large  contours  a  piece  of  a  porcelain 
tooth  of  the  proper  color  can  be  placed  in  the  matrix,  and  the 
body  built  arouiid  and  over  it.  This  prevents  excessive  contrac- 
tion and  simplifies  the  construction  of  a  sharp  corner.  After  one 
of  the  bakings  the  matrix  may  be  fitted  to  the  cavity,  the  position 
of  the  porcelain  examined,  and,  should  any  point  of  the  piece  of 
porcelain  tooth  project,  it  can  be  trimmed  off  with  a  corundum 
wheel.  The  porcelain  should  then  be  washed  and  cleaned  of  the 
debris  resulting  from  the  grinding. 


PORCELAIN  INLAYS. 


325 


In  all  inlays  it  is  preferable  to  have  the  edges  a  little  too  low 
rather  than  too  high.  If  the  porcelain  is  too  high  it  can  be  ground 
down  and  still  give  good  results,  but  the  original  gloss  is  to  be  pre- 
ferred. 

Good  edges  are  difficult  to  obtain  in  porcelain  inlays  smaller 
than  a  pinhead  when  made  in  a  matrix.  In  such  cases  the  use 
of  the  porcelain  rod  method  is  preferable. 

In  small  labial  inlays,  unless  the  cavities  are  deep,  the  cement 
will  show  through  the  porcelain  in  such  wise  as  to  mar  the  in- 
tended effect. 

An  inlay  should  fit  the  cavity  perfectly  and  not  rock  or  move 
when  in  place,  and  the  occlusion  must  be  correct.  The  edges 
should  be  absolutely  exact  and  not  perceptible. 

Porcelain  inlays,  in  the  opinion  of  the  author,  should  be  lim- 
ited to  that  class  of  operations  where  the  question  of  the  exposure 
of  a  metallic  filling  is  to  be  avoided  viewed  from  an  esthetic  rather 
than  from  a  practical  standpoint.  The  advantages  and  durability 
of  gold  and  amalgam  fillings,  as  tooth-savers,  have  been  too  long 
and  too  well  established  to  properly  permit  of  their  supersedure 
by  a  cemented  inlay,  formed  of  an  unyielding  material  like  porce- 
lain, except  where  the  question  of  esthetics  is  a  factor.  If,  around 
the  entire  circumference  of  a  porcelain  inlay  when  cemented  in  the 
cavity  there  exists  a  single  point  where  the  adaptation  is  imper- 
fect, that  point  is  vulnerable  with  even  the  best  cements  so  far 
offered  to  the  profession.  A  corresponding  imperfection  in  a 
gold  inlay,  if  formed  according  to  most  recent  methods,  may  be 
remedied  by  the  burnishing  given  its  f eatlier  edge  against  the 
margins  of  the  cavity  before  and  after  cementation  in  the, final 
finishing  of  the  inlay. 

PORCELAIN    TIPS. 

Porcelain  work  is  specially  adapted  to  the  restoration  of  por- 
tions of  natural  teeth  which  have  been  broken  off  and  of  those 
which  have  suffered  through  some  forms  of  abrasion. 

Pig.  612  represents  the  restoration  of  a  broken  central  incisor. 
Three  pins  were  used  to  retain  the  platinum  cap,  Fig.  613,  which 
v/as  constructed  as  described  in  the  discussion  of  gold  tips  on  page 
131.  One  of  the  pins  of  the  porcelain  tooth  was  removed;  the 
other  was  retained  and  bent  against  the  cap,  and  soldered  to  it 


326 


ARTIFICIAL  CROWN- AFD  BRIDGE-WORK. 


with  pure  gold.     The  palatal  side  of  the  porcelain  tooth  was  then 
contoured  and  attached  to  the  cap  with  porcelain  body. 

Fig.  614  illustrates  a  case  of  atrophy  in  which  the  tips  of  the 
central  incisors  were  contoured  with  porcelain  by  Dr.  G.  H.  Land. 
The  right  central  shows  the  porcelain  in  position,  the  left  the 
porcelain  tip  ready  to  be  adjusted.  A  dovetailed  cavity  was  first 
formed  in  the  central  portion  of  the  section  to  be  tipped  or  con- 
toured.    A  piece  of  platinum  foil  was  adapted  to  the  cavity,  and 


Fig.  612. 


Fig.  613. 


Fig.  614. 


high-fusing  porcelain  body  baked  thereon  as  already  described. 
The  platinum  foil  was  then  removed  and  the  tip  cemented  in 
position. 

To  form  an  extremely  strong  porcelain  tip,  Dr.  Land  selects  an 
S.  S.  White  Dental  Manufacturing  Company's  porcelain  tooth  of 
the  correct  shade,  pulverizes  finely  the  portion  corresponding  to 
the  part  to  be  restored,  and  uses  the  powder  as  the  body  to  form 
the  tip.  A  very  high  heat  is  required  to  fuse  the  porcelain  of 
artificial  teeth,  but  the  greatest  possible  strength  in  a  porcelain  tip 
is  secured  by  the  use  of  such  a  body. 


CHAPTEE   11. 


PORCELAIN  AND  PLATINUM  CKOWNS. 


Fig.  615. 


Fig.  616. 


A  Porcelain  and  Platinum  Collar  or  Partial-Collar  Crown. — 
A  collar  or  partial-collar  cap  is  first  constructed  and  fitted  to 
the  end  of  the  root,  as  illustrated  in  Figs.  615  and  616,  according 
to  one  of  the  methods  described  at  page  113.  The  post  should  be 
long  enough  to  extend  beyond  the  cap.  A  suitable  cross-pin 
tooth  is  selected,  and  ground  and  fitted  on  the  cap.  Usually  it 
will  be  necessary  to  reduce  the  post  in  thickness  and  to  grind  a 
groove,  for  its  reception,  in  the  porcelain  tooth  between  the  pins, 
to  allow  the  tooth  to  assume  its  proper 
position  on  the  cap,  as  shown  in  Fig. 
615.  The  pins  should  be  soldered  to 
the  post  unless  they  can  be  bent 
iaround  it  in  such  a  manner  as  to 
retain  the  porcelain  tooth  in  position 
during  the  baking  of  the  porcelain 
body. 

The  soldering  of  the  sections  of  the 
cap  or  the  pins  should  be  done  with 
ithe  least  possible  quantity  of  pure 
gold. 

Another  method  is  to  cut  the  post 
off  nearly  to  the  surface  of  the  cap, 
and  when  the  porcelain  tooth  is  in- 
vested, bend  the  pins  down  on  the  cap  and  post,  and  connect  with 
solder,  as  seen  in  Fig.  616. 

In  either  case  porcelain  body  is  next  applied,  and  the  por- 
celain front  and  cap  properly  united  and  shaped.  Should  the 
upper  edge  of  the  porcelain  tooth  extend  over  and  beyond  the 

327 


328  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

cap  or  collar,  the  aperture  should  be  filled  in  with  porcelain  body 
and  baked.  The  collar  also  can  be  enameled  at  this  point  if 
desired. 

A  'porcelain  and  platinum  croiun  without  a  collar  is  made  by 
fitting  into  the  root  a  substantial  iridio-platinum  post,  a  Logan 
post  for  instance,  and  capping  the  root  with  a  disk  of  platinum  as 
described  on  page  111.  A  porcelain  front  is  then  fitted  and 
mounted  on  the  cap  as  just  described. 

Porcelain  and  Platinum  JacJcet  Crown. — This  crown  combines 
the  good  qualities  of  many  of  the  best  forms.     In  many  cases 
it  affords  results  which  cannot  be  so  well  obtained  by  any  other 
method.     It  permits  the  restoration  by  crown- 
work  of  a  tooth  without  the  exhibition  of 
Ul  metal  at  the  labial  aspect,  and  without  de- 

L__^-\     struction  of  the  pulp.     It  requires  the  least 
'     \    "      J     possible  removal  of  tooth-structure  to  permit 
\      ,y       the  mounting  of  the  crown.      It  combines 
\    /         1.  }—-y  natural  appearance  and  strength,  and  admits 

of  the  performance  of  operations  of  a  most 
arl,istic  character.  The  jacket  crown  consists  of  a  oone-shaped 
platintim  and  porcelain  cap  fitted  over  the  natural  crown  or  so 
much  of  it  as  remains. 

The  crowning  of  a  central  incisor  will  serve  as  a  typical  case. 
Fig.  617  represents  the  shape  of  the  prepared  tooth.  If  the  crown 
is  broken; off  or^decayed  to  the  gum-margin,  a  post  is  inserted  in 
the  stump  and  shaped  with  amalgam  to  a  somewhat  conical 
form.  A  collar  of  platinum  (No.  30  gauge),  the  full  length  the 
crown  is  to  be,  is  made  and  .fitted  to  the  prepared  tooth  or  root. 
The  lines  of  the  palatal  and  labial  surfaces  of  the  adjoining  teeth 
are  marked  on  the  platinum.j  The  palatal  portion  of  the  collar  is 
cut  away  to  this  line,  so  as  to  clear  the  lower  teeth  in  occlusion  (Fig. 
618).  A  piece  of  platinum,  of  the  same  gauge,  is  soldered  over  the 
collar,  to  form  the  palatal  wall.  The  cap.  is  fitted  in  the  mouth., 
and  the  labial  section  of  the  collar  ground  thin  enough  to  ena.ble 
the' piatihum  to  be  pressed  and  burnished  against  the  tooth  or 
the  built-up  amalgam.  If  this  cannot  be  done  satisfactorily,  trim 
off  the  platinum  the  same  as  on  the  palatal  side  and  solder  a  piece 
of  platinum  foil  over  the  part  instead.     It  must  be  remembered 


PORCELAIN  AND  PLATINUM  CROWNS.  329 

that  in  this  soldering  platinum  solder  should  be  used,  or  only 
the  least  possible  quantity  of  pure  gold.  At  this  stage  the  cap 
will  assume  the  form  seen  at  Fig.  619.  A  thin  veneer  of  porcelain 
(A,  side  view  Fig.  619),  to  represent  the 
tooth,  is  now  ground  and  fitted,  and  held  in  Fig.  619,  Fig.  620. 
proper  position  by  the  porcelain  body  (see 
chapter  on  Porcelain  Teeth:  Veneers).  It  a 
is  possible  to  fit  the  cap  and  veneer  in  the  ;  ■ 
mouth  when  thus  held  by  the  body,  if  con- 
sidered necessary.  The  body  is  next  care-^  \ 
fully  dried  and  fused  in  the  furnace.  The 
crown  is  again  fitted  in  the  mouth,  and  all  requirements,  such  as 
size,  shape,  and  thickness,  and  necessary  changes  noted.  If  the 
surface  of  the  veneer  requires  grinding,  it  should  be  done  at  this 
stage  so  that  it  can  be  glossed  in  the  final  baking,  which  should  be 
strong  and  uniform.  After  the  final  baking  the  exposed  surface 
of  the  platinum  should  be  polished.  The  crown  should  be 
cemented  with  a  thin  mixture  of  oxyphosphate. .  Fig.  620  repre- 
sents the  finished  crown. 

A  Porcelain  and  Platinum  Bicuspid  Crown  with  Metallic  Oc- 
cluding Surface  is  made  as  follows :  The  tooth  or  root  is  prepared 
the  same  as  for  an  all-gold  crown  and  enough  of  the  labial  section 
removed  to  allow  for  the  veneer  (see  Fig.  621).  If  badly  broken 
down  it  should  be  built  up  with  a  post  and  amalgam  (see  page 
39).  A  collar  of  platinum  is  made  and  fitted  the  same  as  for  an 
all-gold  crown,  and  trimmed  free  of  the  occluding  teeth.  A  suit- 
able grinding-surface  is  made  by  stamping  up  a  piece  of  annealed 
iridio-platinum  plate,  iSTo.  30  gauge,  or  heavier,  if  the  case  should 
suggest  it  for  strength.  The  palatal  balf  is  soldered  to  the  col- 
lar, but  the  labial  portion  is  left  unsoldered  and  free  (see  Fig.  622), 
to  permit  the  front  portion  of  the  collar  to  be  manipulated.  The 
labial  section  of  the  collar  is  next  ground  thin  and  pressed  in- 
ward against  the  tooth,  to  make  room  for  the  porcelain  veneer. 
It  will  then  appear  as  shown  at  Fig.  623.  Puncture  the  thin 
platinum  over  the  labial  surface,  and  select  and  fit  a  porcelain 
veneer  to  represent  the  tooth.  Pack  in  porcelain  body  and  fit  the 
veneer  in  position  in  the  mouth.  Carefully  remove  and  bake  in 
the   furnace.      IvText  refit  in   the   mouth,   make   any  necessary 


330 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


changes,  add  more  body,  and  give  the  final  baking.  The  platinuin 
is  then  polished,  after  which  the  crown  is  ready  to  be  cemented. 
Fig.  624  represents  the  finished  crown. 


Fig.  621. 


Pig.  622. 


Fig.  623. 


Fig.  624. 


Fig.  625.   Fig.  626. 


The  form  of  crown  just  described  can  be  used  in  bicuspids  in  all 
cases,  more  especially  where  there  is  a  close  occlusion.  In  bridge- 
work,  a  porcelain  front  backed  with  gold  can  be  soldered  to  this 
form  of  crown  to  represent  a  first  bicuspid,  the  precaution  being 
used  to  heat  and  cool  the  investment  slowly. 

Porcelain  and  Platinum  Bicuspid  Crown  with  Porcelain  Oc- 
cluding Surface. — When  the  natural  tooth  is  broken  down  and 
pulpless,  the  following  method  can  be  practiced:  A  platinum  col- 
lar is  made  and  fitted,  the  same  as  for  the  method  just  explained. 
The  edge  of  the  collar  should  clear  the  occluding  teeth  about  one- 
thirty-second  of  an  inch  (see  Fig.  625).  While 
the  collar  is  in  position  platinum  foil  is  packed 
in,  over  and  around  the  end  of  the  root  or  any 
part  of  the  natural  tooth  present  (A).  Porce- 
lain body  is  then  packed  in  on  the  platinum 
foil  and  the  cavity  filled  even  with  the  edge 
of  the  collar.  The  veneer  is  placed  in  position 
against  the  porcelain  body  and  the  body  packed 
around  it.  The  crown  is  then  carefully  re- 
moved and  baked.  After  baking  it  is  placed  in  the  mouth,  the 
occlusion  noted,  the  cusps  properly  shaped  with  body,  and  the  final 
fusing  of  the  porcelain  performed.  Fig.  626  illustrates  the  com- 
pleted crown. 

Porcelain  and  Platinum  Tuhe  Crown. — This  crown  is  for  use 
in  cases  where  the  natural  crown  is  absent  to  the  line  of  the  cervix 
and  a  metallic  collar  is  not  required. 

The  root  is  ground  even  with  the  margin  of  the  gum.     A  How 


PORCELAIN  AND  PLATINUM  CROWNS.  331 

or  an  iridio-platinnm  post  is  fitted  and  cemented  in  the  root,  and 
amalgam  is  packed  around  its  base,  as  seen  in  section  in  Fig.  627. 
Take  a  piece  of  wire,  of  the  gauge  of  the  post,  and  twist  platinum 
foil  around  it  so  that  the  foil  shall  form  a  tube.  Slip  the  tube 
on  the  post  in  the  root.  Cut  a  disk  of  platinum  foil  fully  the  size 
of  the  end  of  the  rootj  puncture  it  in  the  center,  and  slip  it  over 
the  tube  in  the  post.  Draw  off  tube  and  disk  carefully,  and  solder 
them  together  with  the  smallest  possible  quantity  of  pure  gold. 
This  forms  a  combined  tube  and  cap.  Adjust  in  the  mouth  and 
burnish  the  edges  of  the  platinum  disk  closely  to  the  root.  Pack 
porcelain  body  in  a  thick  paste  around  the  tube  and  fit  a  veneer 
(see  rig.  627)  in  proper  position  against  the  body,  remove,  and 
bake.  After  baking,  place  the  crown  in  position,  burnish 
the  platinum  thoroughly  at  the  gum  line,  and  trim  off  I^'ig.  62' 
the  excess.  Add  body  where  required  and  give  the 
final  baking.  It  is  optional  whether  the  platinum  is 
allowed  to  remain  on  or  not,  but  the  front  portion  is 
generally  removed  for  the  sake  of  appearance.  Fig.  627 
shows  the  finished  crown  in  section.  Should  this  crown 
fracture  in  use  it  can  be  replaced  without  disturbing  the 
post  in  the  root. 

The  methods  in  porcelain  and  platinum  crown-work 
described  are  those  specially  identified  mth  it,  but  porce- 
lain work  can  be  still  further  extended  by  substituting  platinum 
for  gold  in  many  operations  described  under  gold  crown-work. 

PORCELAIN    INLAYING    OF    GOLD    CROWNS. 

Gold  seamless  crowns,  as  the  ''Evans  crowns,"  can  be  easily 
inlaid  with  porcelain  body.  Properly  fit  and  articulate  an  Evans 
gold  crown  to  the  tooth  or  root.  In  some  cases  this  will  be  facili- 
tated by  taking  an  impression  of  the  natural  crown  in  a  tube  with 
plaster,  making  a  fusible  metal  die,  and  giving  the  gold  crown 
the  exact  shape  of  the  natural  tooth,  the  same  as  described  on 
page  109,  the  operation  requiring  but  a  few  minutes.  Place  the 
fitted  crown  in  the  mouth,  with  a  sharp  instrument  mark  the  labial 
portion  of  the  gold  that  is  exposed  to  view,  and  remove  the  crown. 
With  a  small  corundum  wheel  thin  the  part  marked  to  about  the 
thickness  of  'Eo.  60  foil,  and  puncture  it  in  several  places,  as  shown 
in  Fig.  628.     The  narrow  line  of  the  cervico-labial  portion  of  the 


332  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

gold  under  the  gum  must  be  left  intact.  The  crown  is  now  placed 
in  the  mouth  and  the  thinned  labial  section  is  pressed  inward 
against  the  natural  tooth,  to  give  depth  and  strength  to  the 
porcelain  inlay.     If  necessary,  the  natural  tooth  must  be  trimmed 

Fig.  628.  Tig.  629. 


sufficiently  to  permit  this  allowance.  The  gold  at  the  point  A, 
Fig.  629,  should  be  slit  across  the  line  of  the  grinding-surface  and 
pressed  inward,  leaving  an  opening.  This  opening  permits  the 
porcelain  body  to  be  well  anchored  and  given  a  thick  base  for 
strength  at  this  point.  A  suitable  shade  of  the  "Jenkins  porce- 
lain" body  is  selected,  and  applied  to  the  prepared  section  and 
inside  the  grinding-surface,  the  same  as  to  the  matrix  of  an  inlay. 
The  crown  is  next  placed  in  position  on  the  natural  tooth  in  the 
mouth  and  removed.  This  imparts  to  the  porcelain  body  iijside 
an  exact  impression  of  the  form  of  the  natural  tooth,  which,  in 
the  first  baking,  is  slightly  enlarged  by  the  contraction  of  the 
porcelain,  and  assures  a  slight  space  between  the  tooth  and  the 
porcelain.  The  porcelain  also  strengthens  the  grinding-surface 
and  renders  thickening  with  metal  unnecessary.  The  crown  is 
placed  in  the  baking  cup  on  the  bed  of  pulverized  asbestos  (see 
„  rig.  630),  and  the  body  fused  in  the 

_ ,^  same  manner  aS  an  inlay.     Three 

applications   of   body   and   bakings 
will  be  necessary. 

A  porcelain  veneer  caii  be  at- 
tached to  a  gold  crown  with  the 
Jenkins  porcelain  body  by  the  same 
process.  Grind  and  shape  the  veneer  to  fit  the  edges,  and  properly 
fill  the  indented  section  of  the  gold  crown  (see  Veneers,  chapter 
on  Porcelain  Teeth).  Place  the  porcelain  body  in  position,  press 
the  porcelain  veneer  to  place,'  and  fuse.  The  veneer  may  not  be- 
come attached  at  the  first  fusing,  on  account  of  the  shrinkage  of  the 
body.  So  much  the  better  if  it  does  not,  as  more  body  can  now 
be  placed  under  the  veneer  and  the  next  fusing  will  solidly  secure 


PORCELAIN  AND  PLATINUM  CROWNS.  333 

ic.  Next  fill  in  all  interstices  around  the  veneer  and  give  the 
final  fusing. 

Where  a  veneer  is  used  with  the  Jenkins  porcelain,  there  is  not 
so  much  danger  of  changing  the  shade  of  the  porcelain  veneer 
by  repeated  bakings,  as  with  a  higher-fusing  body. 

A  seamless  platinum  crown  can  be  inlaid  in  a  similar  man- 
ner with  high-fusing  porcelain  body.  Platinum  imparts  to  the 
margins  of  the  inlay  a  less  agreeable  shade  than  gold.  This  can  be 
remedied,  in  a  measure,  by  apj)lying  with  a  brush  to  the  margins 
of  the  platinum  and  close  to  the  inlay  a  thick  mixture  of  the 
preparation  of  chlorid  of  gold  used  to  decorate  china,  and  which 
fuses  in  the  furnace  at  the  melting  point  of  gold. 

With  high-  and  low-fusing  porcelain  on  hand,  and  proper  means 
of  fusing,  an  ingenious  dentist  can  find  a  multitude  of  ways  to 
use  both  grades  to  practical  advantage. 

THE  RESPECTIVE  MERITS  OF  VARIOUS  GRADES  OF 
PORCELAIN  FOR  DENTAL  OPERATIONS. 

High-  and  low-fusing  body  porcelains  diifer  considerably  in 
character.  Their  suitability  for  certain  classes  of  operations  must 
materially  vary  also.  At  the  present  time  operators  in  porcelain 
work  generally  express  a  preference  for  some  one  of  the  special 
grades  of  porcelain  and  use  it  to  the  entire  exclusion  of  others. 
This  is  probably  attributable  in  great  measure  to  the  fact  that  as 
yet  the  knowledge  and  experience  of  a  large  proportion  of  inlay 
workers  is  confined  to  the  grade  they  have  in  use  and  the  methods 
associated  and  apparatus  connected  with  it. 

The  value  of  the  respective  grades  of  porcelain  for  the  work  in 
hand  is  governed  by  the  resemblance  to  tooth-structure,  density, 
strength,  permanency  of  structure,  retention  of  form  in  the 
process  of  fusing,  close  adaptation  of  the  finished  inlay  to 
the  margin  of  the  cavity,  and  lastly, — a  most  important  fac- 
tor,— practicability  in  application.  Porcelain  dense  and  strong 
enough  for  use  as  an  ordinary  labial  inlay  might  be  deficient 
in  the  properties  requisite  to  the  formation  of,  for  instance, 
an  incisive  edge  for  an  incisor  tooth,  which  would  demand 
the  greatest  possible  strength  that  can  be  obtained  in  porce- 
lain, j^either  would  porcelain  body  designed  to  form  an  incisive 
edge,  approaching  in  character  body  such  as  composes  artificial 


334  AR  TIFWIAL  CR  0  WN-  A  ND  BRIDGE-  I  YORK. 

teeth, — the  pulverized  artificial  tooth  being  used  by  some  for  the 
purpose,  requiring  a  most  intense  heat  to  fuse  it, — be  as  suitable, 
even  judged  from  a  practical  standpoint,  for  use  in  forming  an  in- 
lay. A  high-fusing  body  is  used  by  some  to  form  the  foundation 
and  one  or  two  successively  lower-fusing  ones  for  shaping  and 
fi.nishing.  For  instance,  a  porcelain  tooth  may  be  devitrified  by 
heating  and  plunging  into  water,  and  then  ground  in  a  mortar  into 
a  fine  powder.  This  powder  may  then  be  used  as  a  porcelain  body 
to  form  the  foundation.  After  it  has  been  fused  the  "Close" 
porcelain  body  is  next  added  and  fused,  and  a  still  lower-fusing 
porcelain  applied  to  finish  with.^ 

All  grades  of  porcelain  shrink  in  fusing.  This  shrinkage  seems 
more  controllable  in  a  low-fusing  porcelain  than  in  a  higher  grade, 
possibly  owing  to  the  high  heat  required  by  the  latter  or  to  the 
development  in  it  of  a  greater  force  of  contraction. 

According  to  the  conditions  discussed,  the  use  seems  to  be  sug- 
gested, in  the  present  development  of  the  art,  of  low-fusing  porce- 
lain, which  combines  the  required  properties  for  inlays  at  labial 
and  approximal  surfaces,  and  of  high-fusing  porcelain  for  inlays 
at  or  extending  to  the  grinding-surface  or  incisive  edge  and  for 
crown  operations,  where  a  porcelain  as  nearly  analogous  in  struc- 
ture to  an  artificial  tooth  in  part  or  whole  is  required. 

^A  comparative  grade  of  fusing  points  of  various  makes  of  porcelains,  placing 
Jenkins  as  the  lowest,  is  as  follows  :  Jenkins,  Ash's  High-fusing,  Whiteley,  Close, 
the  porcelains  of  an  artificial  tooth. 


CHAPTER    III. 


POECELAIN  BKIDGE-WORK. 


Porcelain  bridge-work  consists  of  a  base  or  framework  of 
platinum  covered  with  porcelain,  which  is  fused  to  it.  Owing  to 
the  unalterable  character  and  continuity  of  its  surface,  and  the 
incorruptibility  of  the  material,  it  has  advantages  as  a  denture 
when  permanently  inserted.  In  comparison  with  gold  work  its 
construction  is  less  laborious,  but  its  insertion  and  attachment  to 
the  abutments  is  a  more  complex  operation. 

In  practical  application  the  scope  of  porcelain  bridge-work  is 
limited.  This  is  owing  to  the  fact  that  the  occluding  surfaces 
of  the  teeth  forming  the  bridge  are  not — neither  can  they  very 
well  be — formed  of  or  protected  with  metal.  In  close  bites  and 
where  great  force  is  exercised  in  occlusion,  or  where  the  bridge  is 
of  great  length,  unprotected  porcelain  is  unequal  to  the  strain. 

In  porcelain  bridge-work  the  metallic  structural  frame  should 
be  calculated  on  as  constituting  the  strength  of  the  bridge.  It 
should  be  formed  so  as  to  interfere  with  the  continuity  of  the 
structure  of  the  porcelain  in  the  least  possible  degree.  By  such 
an  arrangement  of  the  metallic  section  the  greatest  degree  of 
strength  is  developed  in  the  porcelain. 


Fig.  631. 


Fig.  632. 


Fig.  633. 


Fig.  634. 


Figs.  631  and  632  represent  an  improper,  and  Figs.  633  and 
034  the  proper,  placing  of  the  bar  in  a  tooth  and  in  a  bridge  in 

385 


336 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


porcelain  work.  In  Fig.  631  the  continuity  of  the  porcelain  is 
broken  by  the  presence  of  the  bar  in  the  center.  Fig.  633  shows 
the  bar  at  the  base  united  to  a  cap  or  saddle.  The  bar  as  shown 
in  Fig.  634,,  united  to  the  caps  and  saddle,  affords  far  greater 
strength  and  rigidity  than  either  would  separately  as  illustrated 
in  Fig.  632,  largely  through  avoiding  interruption  of  the  con- 
tinuity of  the  structure  of  the  porcelain. 

The  metallic  portion  of  the  bridge,  consisting  of  the  caps  on  the 
piers  and  the  metal  spanning  the  space  between  the  abut- 
ments, must  be  so  solidly  united,  rigid,  and  strong,  as  to  provide 
independently  of  the  porcelain  the  necessary  strength  for  the 
structure.  Should  a  platinum  crown  be  used  on  one  of  the  piers, 
the  end  of  the  bar  must  be  flattened  and  extended  well  around  on 
the  palatal  side  of  the  crown,  and  securely  attached  with  platinum 
solder. 

Porcelain  bridge-work  is  now  almost  universally  constructed 
with  the  teeth  forming  the  bridge  resting  on  a  metallic  plate  or 
saddle  of  the  width  of  their  bases.  In  a  case  where  a  saddle  is 
not  used,  a  heavy  triangular  or  half-round  bar  (A,  Fig.  635)  of 

Fig.  636. 


iridio-platinum,  in  connection  with  a  flattened  cross  and  upright 
bar,  as  shown  in  Figs.  635 -and  636,  may  be  used,  This  latter 
style  leaves  a  self -cleansing  space  under  the  bridge,  which  is  not  as 
desiralble  as  a  saddle,  especially  for  upper  cases  of  porcelain  bridge- 
work.  The  contour  of  the  palatal  side  in  the  saddle  form  is  more 
agreeable  to  the  patient,  and  experience  shows  that  in  most  cases, 
\\:here  details  of  construction  have  been  properly  carried  out,  it  is 
more  cleanly.  Experience  also  shows  that  the  percentage  of  cases 
in  which  absorption  of  the  alveolar  ridge  takes  place  to  any  great 
extent  is  so  small  as  not  to  be  eonsidered,  in  view  of  the  advan- 
taffes  that  are  otherwise  obtained. 


I'OIWKLAIN  BRIDGK-WORK.  337 

The  case  illustrated  in  Fig.  637  is  presented  as  typical,  to  il- 
lustrate the  construction  of  a  piece  of  porcelain  bridge-work.  The 
cuspid  and  molar  roots  are  capped  with  platinum,  and  iridio-plati- 
num  posts  inserted,  that  of  the  molar  cap  in  the  palatal  root.  The 
caps  and  posts  are  soldered  with  25  per  cent,  platinum  solder.  An 
impression  is  taken  of  the  alveolar  ridge  and  a  platinum  saddle 
struck  up  to  span  the  space.  The  platinum  is  cut  to  the  size 
of  the  combined  bases  of  the  artificial  teeth  which  are  to  rest  upon 
it.  The  caps  are  placed  in  the  mouth,  an  impression  is  taken, 
and  the  caps  withdrawn  in  position  in  the  impression.  The  struck- 
up  saddle  is  turned  upside  down,  trimmed,  fitted,  and  placed 
in  position  between  the  caps  on  the  surface  of  the  plaster  impres- 

Fio.   637. 


sion.  The  gauge  of  the  platinum  is  to  be  decided  by  the  operator. 
If  the  gums  are  exceedingly  hard  and  unyielding,  ISo.  31  to  32 
gauge  should  be  used,  varying  from  that  to  ISTo.  22  gauge  as  the 
gums  are  soft  and  spongy, 

The  impression  with  the  saddle  in  position  is  filled  with  a  mix- 
ture composed  of  two  parts  plaster,  two  parts  shredded  asbestos, 
and  one  part  calcined  marble-dust,  to  form  a  model.  On  the  re- 
moval of  the  plaster  impression,  the  platinum  saddle  will  be  found 
imbedded  in  the  model  to  the  depth  of  the  thickness  of  the  plati- 
num used.  In  this  manner  a  uniform  pressure  of  the  saddle  on 
the  gums  is  secured,  which  cannot  properly  be  effected  by  scraping 
so  large  a  surface  of  plaster. 

Another  method  of  obtaining  a  similar  result  is :  Strike  up  on  the 
die  a  piece  of  sheet  lead  rolled  to  the  desired  gauge  and  of  the 
size  the  saddle  is  to  be,  and  place  it  on  the  impression  between 
the  caps,  in  the  same  manner  as  has  been  described  regarding  the 
platinum  saddle.  Run  the  model  and  then  remove  the  impression. 
The  removal  of  the  lead  will  exhibit  a  uniformly  depressed  space 

23 


338  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

on  the  model,  into  which  the  struck-up  platinum  saddle  can  be 
fitted.  By  this  latter  method  any  degree  of  pressure  on  the  al- 
veolar ridge  on  the  part  of  the  saddle  is  obtained  and  any  gauge  of 
platinum  desired  can  be  used. 

An  iridio-platinum  cross-bar,  made  of  ISTo.  14  gauge  round  wire 
flattened  to  jSTo..  16  gauge  and  set  on  edge,  is  extended  from  the 
post  of  one  cap  to  the  post  of  the  other,  fitting  closely  against  or 
on  the  posts,  and  resting  on  the  caps  and  saddle  (see  Fig.  637). 
The  saddle  is  next  soldered  to  the  caps,  and  the  cross-bar  to  the 
caps  and  saddle,  with  20  per  cent,  platinum  solder.  To  retain 
the  bar  in  position  on  the  caps,  a  little  investing  material  should 
be  placed  crosswise  over  the  bar  in  the  center  of  the  investment; 
as  soon  as  the  saddle  and  the  ends  of  the  bar  are  soldered,  this  little 
piece  of  investment  is  removed  and  the  soldering  of  the  bar  com- 
pleted. This  frame-work  makes  a  metallic  structural  foundation 
for  the  bridge,  the  strength  and  rigidity  of  which  will  not  be  im- 
paired in  fusing  on  the  porcelain  body.  Body  such  as  "Close's" 
fuses  at  a  temperature  which  will  not  melt  a  grade  of  platinum 
solder  above  15  per  cent.  The  piece  is  next  adjusted  in  the 
mouth,  the  caps  held  solidly  in  position,  and  the  platinum  pressed 
and  burnished  against  the  tissues  at  any  spots  that  seem  to  suggest 
it,  and  at  the  edges,  sufiiciently  to  make  a  white  line  at  the  margin, 
but  not  enough  to  cut  into  the  tissues.  This  is  not  done  for  the 
purpose  of  obtaining  alveolar  support,  but  for  the  exclusion  of 
particles  of  food  from  under  the  bridge,  a  condition  that  is  main- 
tained even  though  slight  absorption  of  the  membrane  should 
supervene.  Impression  compound  is  next  placed  on  the  bridge 
and  an  impression  of  the  occluding  teeth  taken.  ]^[ext  wax  is 
placed  inside  each  of  the  caps  to  exclude  the  plaster  and  render 
removal  easy,  and  plaster  articulating  models  are  made.  Facings, 
or  suitable  teeth  with  long  pins,  are  selected  and  the  under  side 
of  the  pins  ground  flat,  to  present  a  larger  surface  of  contact  to 
the  bar.  The  facing-s  are  ground,  fitted,  waxed  in  position,  the 
bridge-work  removed  for  the  model,  and  invested  in  plaster  and 
asbestos.  The  wax  is  removed,  each  pin  is  bent  down  in  close 
contact  mth  the  bar  and  soldered  to  it  with  the  least  possible 
quantity  of  pure  gold;  the  case  is  then  removed  and  boiled  in 
acid.  Pure  gold  is  used  for  this  soldering,  as  the  heat  required 
to  flow  platinum  solder  would  be  liable  to   etch  the  invested 


I'ORCKLAIN  BRIDGE-WORK.  339 

porcelain  teeth.     Fig.  637  shows  the  appearance  of  the  bridge  at 
this  stage  of  the  construction. 

Porcelain  body  such  as  is  used  in  continuous-gum  work  is  ap- 
plied in  a  similar  manner  to  the  case.  Interstices  are  filled,  grind- 
ing-surfaces  and  cusps  which  are  to  be  formed  are  built  up  and 
contoured  as  much  as  possible  for  the  first  baking.  For  the  next 
baking  more  body  is  added,  shrinkage  being  allowed  for  and 
remedied.  More  than  two  bakings  are  seldom  necessary.  The 
heat  should  be  sufficient  to  thoroughly  fuse  the  body,  give  a 
glazed  surface,  and  develop  the  strength  of  the  porcelain.  Fig. 
G-38  illustrates  the  bridge  ready  for  cementation. 

Fig.  638.  Fig.  639. 


A  case  of  porcelain  bridge-work,  such  as  has  been  described,  is 
best  cemented  with  gutta-percha.  (See  Part  II,  Chapter  XII: 
Cementation.) 

Fig.  639  represents  a  porcelain  extension  bridge  in  which  the 
support  consists  of  a  crown  and  bar  combined. 

In  porcelain  bridge-work  artificial  gum  to  a  moderate  amount 
can  be  formed  above  the  teeth  of  the  bridge. 

Fig.  640  represents  a  case  by  Dr.  M.  L.  Khein.  To  remedy 
the  abnormal  character  of  the  occlusion,  the  lower  anterior  teeth 
and  the  right  upper  cuspid  were  trimmed  to  the  dotted  line  seen 
in  the  figure.  To  replace  the  missing  teeth  porcelain  bridge- 
work  was  then  constructed.  The  lateral  and  central  roots,  and 
the  right  cuspid  and  the  molar,  constituted  the  abutments.  On 
the  central  and  lateral  roots  were  mounted  caps  with  collars.  A 
platinum  crown  was  then  made  for  the  cuspid  (Fig.  641),  and 
to  this  crown  was  attached  the  bar,  which  was  extended  to  its 
anchorages  in  the  molar  crown  and  the  lateral  and  central  roots, 
the  caps  on  the  ends  of  which  the  posts  pierced.  Owing  to  the 
large  quantity  of  porcelain  body  to  be  used  in  forming  the  arti- 


340 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


ficial  gum,  a  strip  of  platinum  plate  was  extended  above  the  bar 
to  stiffen  its  projecting  ends  and  prevent  warpage  in  baking.  The 
artificial  teeth  were  then  articulated  to  meet  the  incisive  edges 
of  the  inferior  natural  teeth,  and  thus  in  a  measure  overcome 


Fig    640. 


i^f 


EiG.  CA'6. 


the  deformity  caused  by  the  abnormal  occlusion.  In  doing  this 
the  labial  aspect  of  the  cuspid  was  covered  by  the  artificial  teeth. 
Porcelain  gum  was  then  formed  above  the  teeth  in  sufficient  quan- 
tity to  restore  the  contour  of  the  parts.  It  was  brought  to  a 
feather'  edge  and  pressed  hard  against  all  the  tissues  to  insure  a 
hygienic  condition.  Fig.  642  shows  the  finished  bridge.  In 
Fig.  643  the  bridge  is  seen  in  position.     The  artistic  result  and 


I'OltCELAIN  BRIDGE-  WORK. 


341 


improved  appearance  effected  are  at  once  apparent.  The  me- 
chanical construction  of  the  piece  was  intrusted  to  Dr.  C.  L. 
Andrews. 

Fig.   044. 


Fig.  644  is  a  lower  bridge  firmly  supported  on  the  right  side  by 
passing  the  bar  through  the  cuspid  and  inserting  the  end  in  the 
pulpless  bicuspid  as  illustrated.  The  pulpless  bicuspid  on  the 
left  constitutes  the  other  abutment. 

PLATINUM    SOLDER 

Gold,  either  pure  or  alloyed  with  platinum,  is  used  as  the  solder 
for  uniting  sections  of  platinum  in  porcelain  work.  ISTo  alloy  of 
the  baser  metals  is  permissible,  because  it  would  affect  the  color  of 
the  porcelain.  On  the  other  hand,  gold  exposed  to  a  temperature 
much  beyond  its  melting  point  in  contact  with  platinum  will  be 
iibsorbed  by  the  latter,  so  great  is  the  affinity  of  the  two  metals. 
In  constructing  the  platinum  frame-work  for  a  porcelain  bridge, 
it  is  necessary,  therefore,  to  use  a  solder  which  will  resist  the  fusing 
temperature  of  the  porcelain;  otherwise,  the  gold  would  be  ab- 
sorbed by  the  platinum,  and  vacuoles  would  be  formed  in  the 
porcelain  at  the  points  from  which  the  solder  was  absorbed,  thus 
weakening  the  piece.  When  a  low-fusing  porcelain  is  used,  pure 
gold  answers  very  well  as  the  solder;  but  for  the  higher-fusing 
porcelains,  which  are  used  in  making  porcelain  bridge-work,  the 
gold  must  be  alloyed  with  platinum,  in  various  proportions,  to  raise 
the  fusing  point,  according  to  the  body  to  be  used. 

Platinum  solders,  for  this  use,  are  made  by  alloying  the  gold 
with  from  5  to  30  per  cent,  of  platinum.     "Close's"  body,  which 


342  ^ ^ TIFICIA L  CRO  WN-  A ND  BRIDGE-  WORK. 

is  largely  used  in  this  work,  fuses  at  about  the  same  temperature  as 
a  15  per  cent,  platinum  solder.  The  fusing  point  of  a  20  per 
cent,  solder  will  be  well  above  that  required  for  this  body.  A 
25  per  cent,  solder  will  stand  any  heat  applied  in  this  line  of  work^ 
except  where  the  body  of  a  porcelain  tooth  is  to  be  fused.  For 
this  a  30  per  cent,  solder  would  be  necessary. 

It  is  well  to  use  a  higher  per  cent,  solder  in  the  early  steps  of 
an  operation  than  in  the  later  stages,  and  thus  avoid  the  possibility 
of  melting  the  first  soldering.  The  melting  of  all  platinum  solders- 
requires  the  use  of  the  compound  blow-pipe. 

FURNACES    FOR    HIGH-FUSING    PORCELAIN. 

A  proper  furnace  is  essential  in  baking  porcelain,  for  which 
small  gas  or  electric  furnaces  or  ovens  specially  designed  for  crown- 
and  bridge-work  are  used.  The  gas  furnaces  are  made  with 
platinum  mufiles  ^m.i\\  an  open  flame.  The  draft  should  always- 
be  sufficient  to  entirely  consume  the  gas  and  carry  oft"  the  prod- 
ucts of  combustion.  If  this  is  neglected,  or  if  the  furnace  is. 
defective,  gases  are  liable  to  penetrate  the  interior  of  the  muffle  and 
"gas"  the  porcelain,  altering  the  color  and  causing  porosity,  a 
condition  that  can  only  be  corrected  by  substituting  new  material. 
Platinum  mufiles,  made  seamless,  are  used  in  preference  to  clay, 
as  the  required  heat  can  be  obtained  in  them  in  from  three  to  five 
minutes.     Fig.  645  illustrates  the  "Land  Midget  Gas  Furnace." 

In  the  electric  furnace  the  heat  is  generated  around  a  small 
muffie  or  oven  by  electricity.  Electric  furnaces  or  ovens  are  a 
little  slower  in  heating  up  to  the  required  temperature  as  com- 
jDared  with  gas,  but  they  have  the  merit  of  under  no  circumstance 
"gassing"  the  porcelain.  Fig.  646  illustrates  the  "Custer  Electric 
Furnace."  A  furnace,  whether  gas  or  electric,  to  meet  all  the 
requirements  for  general  work,  should  be  capable,  if  necessary, 
of  generating  a  heat  of  at  least  3000°  F.,  as  some  operations  in 
porcelain  work  require  that  temperature  to  develop  strength  and 
color.  A  platinum  muffle,  although  seamless,  will  not  assure 
against  "gassing"  the  porcelain.  In  the  use  of  electric  furnaces^ 
the  fine  platinum  wires  which  encircle  the  muffle  and  form  the 
resistance  which  generates  the  heat  require  to  be  renewed  at  in- 
tervals, depending  on  the  frequency  of  use  and  amount  of  heat 
generated. 


PORCELA  IN  Jlh'lDGE-  WOh'K. 

Fig.  ('lib. 


343 


Fig.  646. 


PAET   V. 


MATERIALS  AND  PROCESSES  USED  IN  CROWN-  AND 
BRIDGE-WORK. 


CHAP  TEE    I. 

PLATES   AND   SOLDEES. 

Plates. — In  the  construction  of  crown-  and  bridge-work,  gold, 
platinum,  or  iridio-platinum  is  used  in  the  following  forms  and 
grades  in  carat,  as  suits  the  requirements  of  the  case  and  the 
preference  of  the  dentist: 

Gold  plate,  24  carats,  from  Xo.  28  to  ISo.  30  IT.  S.  standard 
gauge,^  for  constructing  the  collars  and  caps  to  collars  of  crowns 
and  seamless  crowns,  and  for  backing  porcelain  fronts. 

Gold  plate,  slightly  alloyed, — about  23  carats  fine, — in  crown- 
work,  if  less  flexibility  of  the  metal  is  required. 

Gold  plate,  22  carats,  N'o.  28  to  ^o.  30  standard  gauge,  in 
constructing  collars  for  crowns  with  porcelain  fronts  and  all-gold 
crowns  made  in  sections. 

Gold  plate,  20  carats,  in  construction  of  bridge-work. 

Gold  for  constructing  collars  should  be  of  as  high  a  carat  as 
possible,  to  better  resist  the  action  of  acids.  A  large  proportion 
of  copper  as  an  alloy  is  objectionable,  owing  to  its  tendency  to 
cause  tarnishing  of  the  collar  where  an  acid  condition  of  the 
saliva  exists.  For  this  reason.  United  States  gold  coin,  contain- 
ing 10  per  cent.  cojDper,  so  much  used  for  collars,  is  not  quite 
suitable.  It  is  also  too  stiff,  and  collars  made  of  it  are  not  readily 
burnished  to  fit  at  the  edges.  Dr.  J.  J.  R.  Patrick's  formula, 
which  is  equal  parts  of  coin  and  pure  gold,  affords  a  plate  which 
is  decidedly  preferable,  inasmuch  as  the  proportion  of  copper  is 
reduced  to  5  per  cent. 

Gold  plate,  24  carats,  with  a  lining  of  platinum,  can  be  used 
in  any  of  the  processes  connected  with  crown-  and  bridge-work, 
and  is  especially  recommended  to  the  inexperienced,  for  the  rea- 
son that  the  melting  of  a  part  of  a  crown  in  the  soldering  process 

'  The  United  States  standard  is  the  only  gauge  referred    to   in    the  original 
descriptive  matter  of  this  treatise. 

347 


348  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

is  prevented  by  its  use.  It  is  formed  by  placing  together  an  an- 
nealed gold  plate  and  a  platinum  plate  (the  gold  about  l!^o.  20 
gauge  and  the  platinum  No.  30)  and  passing  them  through  a  roll- 
ing-mill, in  which  process  the  plates  are  welded  and  reduced  to  the 
desired  thickness. 

Platinum  and  iridio-platinum  plate  are  used  for  forming  crowns 
for  use  in  connection  with  porcelain  bridge-work.  Platinum  plate 
for  forming  collars  need  not  be  over  ISTo.  30  to  32  gauge.  At 
this  thickness  it  can  be  easily  adapted  to  the  cervix  of  the  tooth. 

Pure  platinum  rolled  very  thin  is  used  for  forming  caps  to 
collars,  backing  teeth,  and  for  various  purposes  connected  with 
this  class  of  operations.  Iridio-platinum  wire  is  used  for  pivots, 
pins,  or  posts,  being  more  rigid  than  pure  platinum.  A  wire 
of  gold  and  platinum  alloy  is  used  on  account  of  its  elasticity 
for  split  or  spring  pivots  or  posts  in  removable  bridge-work. 

Solders. — Gold  solder,  18  and  20  carats  fine,  is  used  for  crowns 
and  bridges,  but  18  is  considered  by  some  too  low  a  carat. 

14  carats  for  strengthening  seamless  crowns;  used  only  in 
crowning  operations. 

Successive  grades  of  solder  from  hard  to  easy  flowing  can  be 
used  in  the  regular  soldering  of  crown-  and  bridge-work;  gold 
plate  or  a  hard-flowing  solder  for  the  first,  a  medium-flowing  sol- 
der for  the  next,  and  an  easy-flowing  one  for  the  finish.  This 
avoids  melting  or  flowing  of  the  gold  at  any  point  previously  sol- 
dered., 

Any  grade  of  solder  can  be  made  according  to  the  following 
formula : 

Zinc,  1^  grs.; 
Pure  gold, 

Silver  solder,  in  quantity  sufficient  to  make  up 
the  22 1^  remaining  parts  in  weight. 

The  quantity  of  silver  solder  used  will  regulate  the  grade  in 
carat  of  the  solder.     Thus : 

Zinc,  1^  grs.; 
Pure  gold,  20  grs. ; 
Silver  solder,  3  grs., 

will,  by  the  burning  out  of  a  portion  of  the  zinc  in  the  process, 
make  a  solder  about  20  carats  fine. 

By  lessening  the  proportion  of  zinc  from  1^  grains  to  1  grain, 


PLATES  AND  SOLDERS.  349 

the  proportion  of  silver  solder  being  kept  the  same,  the  solder 
will  become  harder-flowing  and  a  little  finer. 

Dr.  W.  H.  Dorrance  recommends  the  following  formula  as  an 
alloy  for  the  formation  of  different  grades  of  gold  solders,  the 
proportion  of  the  alloy  used  determining  the  melting-point  and 
fineness  in  carat  of  the  solder: 

1  part  pure  silver ; 

2  parts  pure  zinc  ; 

3  parts  pure  copper. 

The  silver  and  copper  are  first  melted  together  in  a  crucible 
lined  with  borax,  and  the  zinc  added  quickly  in  small  pieces, 
stirring  the  mass  meantime  mth  a  pipe-clay  stem.  It  is  then, 
on  the  fumes  of  the  zinc  passing  off,  immediately  poured  into 
an  ingot-mold  or  into  a  large  wooden  pail  filled  with  water;  4 
grains  of  this  alloy  melted  with  20  grains  of  pure  gold  will  result 
in  a  solder  fully  20  carats  fine. 

As  a  solder  for  crown-  and  bridge-work  constructed  of  22-carat 
gold  plate,  Dr.  Litch's  formula  is  as  follows: 

Gold  coin  (ten  dollars),  258  grs.; 
Spelter  (or  brazier's  solder),  24  grs.; 
Silver  coin,  24  gi-s. 

This  is  a  proportion  of  about  26  grains  of  pure  copper  and 
232  grains  of  pure  gold  to  the  remaining  48  grains  of  the  alloy,, 
and  makes  a  good  solder  a  little  over  18  carats  fine. 

Dr.  C.  M.  Itichmond  originally  used  American  gold  coin  for 
forming  gold  crowns,  rolling  it  out  in  the  form  of  plate.  The 
scraps  he  formed  into  solder  by  melting  and  adding  one-fifth  of 
their  weight  of  fine  brass  wire  cut  in  small  pieces,  using  plenty 
of  borax. 

Dr.  Low's  formula  for  solder  in  bridge-work  is: 

1  dwt.  coin  gold  ; 

2  grs.  copper ; 
4  grs.  silver. 

This  makes  a  solder  about  19  carats  fine. 

The  following  formula^  gives  a  20-carat  solder  which  is  specially 
j-ecommended  for  crown-  and  bridge- work: 

American  gold  coin  (21.6  carats  fine),  $10  piece,  2-58  grs.; 

Spelter  solder,  20.64  grs. 

'  American  System  of  Dentistry,  vol.  iii,  p.  849. 


350  ARTIFICIAL  CROWN- AND  BRIDGE-WORK. 

Hard-flowing  gold  solder,  for  use  in  bridge-work,  is  con- 
veniently made  by  melting  together,  by  weight,  one-third  18  carat 
solder  to  two-thirds  18  carat  gold  plate;  20  carat  solder  and  plate 
can  be  used  in  the  same  proportion  to  form  a  higher  grade.  The 
plate  is  first  melted  and  the  solder  then  added,  and  when  cooled 
rolled  ont  to  desired  gauge. ^ 

Fluxed  Solder  Filings. — Fluxed  gold  solder  filings  are  made 
by  filing  with  a  clean,  flat  plate  file  a  thick  piece  of  solder  held 
in  a  vise.  The  filings  are  allowed  to  fall  in  a  box  or  on  a  sheet 
of  j)aper  placed  to  receive  them.  A  magnet  should  be  passed 
through  the  filings  to  remove  any  minute  particles  of  steel.  To 
five  parts  of  the  filings  so  made  is  added  and  well  mixed  with 
them  one  part  of  the  prepared  flux  or  finely  pulverized  vitrified 
borax.  Solder  prej^ared  in  this  way  is  useful  for  strengthening 
crowns,  and  also  in  fine  soldering  operations,  as  the  particles  of 
the  solder  take  the  heat  separately  and  fuse  much  more  quickly 
than  when  the  solder  is  cut  in  pieces.  The  flow  of  the  solder  is 
also  more  easily  limited. 

1  This  formula  is  the  one  used  by  the  author,  and  is  convenient  and  reliable. 


CHAPTER    II. 

PORCELAIN  TEETH. 

The  qualities  specially  requisite  in  the  body  of  porcelain  teetli 
for  use  in  crown-  and  bridge-work  are  density,  strength,  and  the 
ability  to  withstand  unaltered  in  form  or  shade  any  degree  of  heat 
to  which  they  may  necessarily  be  subjected.  In  these  respects 
the  porcelain  teeth  of  our  best  American  manufacture  seem  to 
excel,  besides  affording  the  most  artistic  imitation  of  the  natural 
teeth  in  form  and  shade.  They  are  also  distinguished  by  the 
practical  location  of  the  pins. 

In  some  crowning  operations,  where  to  imitate  the  conforma- 
tion of  a  natural  crown  considerable  alteration  of  the  labial  sur- 
face of  a  porcelain  front  is  required,  teeth  of  English  manufacture 
may  be  used,  as  the  texture  of  the  porcelain  more  easily  permits 
a  polish  being  given  to  a  ground  surface. 

Teeth  are  sometimes  fractured  in  the  process  of  soldering,  caused 
by  the  contraction  of  the  backing  when  adapted  over  the  edges 
of  the  porcelain  in  a  curve  instead  of  at  a  right  or  slightly  obtuse 
angle,  or  by  melting  solder  on  some  point  of  the  porcelain  which 
is  unprotected  by  a  backing  of  metal.  The  solder,  or  the  borax, 
as  it  cools,  contracting  on  the  porcelain,  or  a  very  thin  edge  of  the 
metal  covering  it,  Avill  usually  cause  a  fracture.  The  porcelain 
tooth  has  yet  to  be  made  that  will,  as  a  rule,  endure  such  extreme 
treatment  without  breaking. 

Veneers.- — A  veneer  consists  of  a  thin  piece  of  porcelain  repre- 
senting the  labial  aspect  of  the  natural  tooth. 

To  form  a  veneer  select  a  porcelain  tooth  of  the  required  shade 

and  size.     On  the  end  of  a  piece  of  wood,  about  the  size  of  the 

tooth,  melt  and  attach  a  mass  of  shellac,  heat  the  porcelain  tooth 

and  imbed  the  labial  surface  into  the  shellac.      Clip  off  the  pins 

and  with  a  corundum  wheel  on  the  lathe  uniformly  grind  down 

the  porcelain  until  the  ends  of  the  pins  are  removed.     Heat  the 

porcelain,  release  the  veneer,  and  remove  all  particles  of  shellac 

before  application  of  veneer  to  case. 

351 


CHAPTEK    III. 

MOLDS  AND  DIES. 

Metallic  models  of  fusible  metal  can  be  easily  and  quickly 
formed  for  use  in  crown-  and  bridge-work.     The  melted  alloy 
can  be  poured  into  a  plaster,  moldine,  or  gutta-percha  impres- 
sion taken  in  a  tube  or  impression-tray.     A  piece 
Fig.  647.         of  copper  plate  or  of  an  old  separating  file,  placed 
between  teeth  as  shown  in  Fig.  64Y,  and  removed 
in  position  in  the  impression,  will  accurately  outline 
the  space  between  the  teeth  in  the  metallic  model. 
When  a  tube  is  used,  a  strip  of  paper  should  be 
wound  around  it  to  lengthen  the  die. 

The  following  fusible  alloys  of  tin  are  suitable 
for  the  purpose: 


Tin. 
1 

PROPORTIONS  OF 

Lead. 
2 

METALS. 

Bismuth. 
2 

MELTING  POINT  OF 
THR   ALLOY. 

Fabr. 
236° 

5 

3 

3 

202° 

3 

5 

8 

197° 

Dr.  G.  W.  Melotte,  of  Ithaca,  IST.  Y.,  to  whom  is  accorded  the 
credit  of  introducing  the  use  of  fusible  metal  and  the  compound 
called  "moldine"  into  crown-  and  bridge-work,  gives  the  propor- 
tions of  his  alloy  in  parts  as — 

Tin,  5  ;  Lead,  3  ;   Bismuth,  8. 

Dr.  Melotte's  moldine,  a  preparation  compounded  of  potter's 
clay  and  glycerin  (to  which,  when  needed  to  soften  it,  more^ 
glycerin  can  be  added),  is  very  useful  in  molding. 

HOW  TO  QUICKLY  MAKE  A  TUBE  AND  FUSIBLE    METAL  DIE. 

Take  a  thin  strip  of  copper  plate,  at  least  35  gauge,  anneal,  and 
bend  it  around  the  tooth  in  the  mouth  or  its  form  on  the  plaster 
model.  Both  ends  of  the  copper  at  the  part  lapped  are  next  cut, 
as  shown  at  A,  Fig.  648,  and  turned  over  tight  and  close  in  the 
manner  seen  at  B.  This  fastens  both  ends  of  the  copper,  which 
when  trimmed  off  at  C  formis  a  tube.  In  this  tube  take  an  im- 
pression of  the  natural  cro^vn,  either  in  the  mouth  with  a  little^ 
352 


MOLDS  AND  DIES. 


353 


plaster  or  moldine  or  from  the  plaster  model  with  moldine  by 
trimming    around    the    tooth    or    bj    separating    it    from    the 
rest  of  the  model.     Encircle  the  tube  with  a  strip  of 
paper.     Hold  the  paper  and  tube  with  a  clamp.     Melt     ^''''  ''^^' 
and  pour  the  fusible  metal  moderately  cool,  and  im- 
merse tube  and  metal  in  water.     This  gives  a  die  with 
a  long  narrow  shank,  which  may  require  to  be  trimmed 
at  the  neck  with  a  file.     When  impression  compound 
or  gutta-percha  is  used,  cool  and  then  dry  the  surface 
with  an  air  syringe  before  pouring  the  fusible  metal. 

A  counter-die  to  a  small  cast  or  die  of  fusible  metal 
IS  made  by  indenting  a  block  of  lead  with  a  punch,  and 
then  driving  the  cast  or  die  into  it.  Its  use  in  crown- 
work  IS  described  on  pages  84,  93,  and  97. 

Dr.  Melotte  has  introduced  for  special  cases  a  novel  method 
of  forming  a  combmation  plaster  and  metal  model,  in  which  the 
parts  representing  the  teeth  are  of  fusible  metal.  The  following 
is  a  description:  The  impression  is  taken  in  plaster.  Iron  pin"^ 
to  act  as  dowels  are  placed  in  the  molds  of  the  teeth.  Pieces  of 
a  fusible  metal  which  melts  at  a  low  point  are  then  melted  into 
each  of  the  molds  with  a  few  puffs  of  the  blow-pipe.  Plaster  is 
then  poured  in  the  remainder  of  the  impression.  The  advantage 
afforded  by  a  model  of  this  kind,  when  gold  attachments  or  clasps 
are  to  be  shaped  to  teeth,  is  obvious.  The  method  applied  in  the 
construction  of  bridge-work  is  given  on  page  153.  Dr.  Melotte's 
formula  for  the  fusible  metal  used  in  the  above  method  is: 

Bismuth,     8  parts ; 
Lead,  4     " 

Zinc,  3     " 

Cadmium,   2     " 
Melts  at  about  150°  F. 

Cuttle-fish,  as  a  molding  material,  affords  means  of  quickly  and 
easily  making  dies  of  grinding-surfaces  of  teeth  with  zinc  or  Bab- 
bitt's metal  as  well  as  fusible  metal.  Press  the  model  of  the  grind- 
ing-surface  into  the  flat  surface  of  the  cuttle-fish  to  the  desired 
depth,  withdraw  model  and  place  a  metallic  ring  pressed  into  the 
surface  of  the  cuttle-fish  around  the  impression.  ISText  pour  in 
the  metal  to  form  the  die. 

24 


Fig.  649. 


CHAPTER   IV. 


SOLDERING. 

Models  and  Investments  for  Solder- 
ing.— Models  on  which,  the  solderiiig  is 
to  be  done  for  bridge- work  are  made  of 
calcined  marble-dust  and  plaster,  in  the 
proportion  of  equal  parts. 

For  small  investments,  such  as  single 
crowns,  2  parts  calcined  marble-dust  and 
1  of  plaster. 

For  large  investments,  including 
pieces  of  bridge-work,  1  part  calcined 
marble-dust,  1  part  common  white  sand, 
and  1  part  plaster.  The  reason  for  the 
use  of  the  latter  proportions  is  that  the 
sand  prevents  the  excessive  contraction 
that  is  liable  to  take  place  in  large  masses 
of  investing  material  entirely  composed 
of  plaster  and  marble-dust  when  sub- 
jected to  great  heat  for  a  considerable 
time.  The  marble-dust  in  combination 
with  sand  renders  the  material  more 
suitable  to  fill  interstices  and  the  insides 
of  caps.  In  cases  of  bridge-work  of  any 
great  size,  a  loop  of  iron  wire  should 
encircle  the  piece  in  the  investment. 
Sulfate  of  potassium,  used  in  place  of 
common  salt,  but  in  smaller  quantity, 
mil  cause  the  mixture  to  set  quickly 
and  hard.  The  best  method  is  to  place 
a  small  teaspoonful  of  the  sulfate  of 
potassium  in  a  pint  bottle  of  water,  and 
thus  have  it  always  ready  for  use  in  the 
proper  proportion.  The  investment 
should  always  be  made  as  small  as  the  case  will  properly  admit. 

354 


SOLDERING. 


365 


Soldering. — When  it  is  desired  to  remove  the  wax  cement  con- 
necting  sections  of  a  crown  or  bridge  in  an  investment  before 
heating,  it  should  be  done  by  pouring  boiling  water  on  the  parts. 
It  is  not  advisable  tO'  remove  the  wax  with  an  instrument,  as  parts 
delicately  held  in  position  are  liable  to  become  displaced.  Many 
prefer  to  let  the  wax  bnrn  out  of  the  investment  as  it  is  heated. 
This  is  always  done  when  fluxed  wax  is  used  and  the  benefit  of  the 
flux  is  to  be  obtained.  The  objection  to  burning  out  wax  is  that 
pits  are  more  liable  to  be  found  afterward  in  the  solder. 

In  soldering  crown-  and  bridge-work  or  sections  of  it  contain- 
ing porcelain  fronts,  the  investment  should  be  first  uniformly 
and  thoroughly  heated.     A  full  flame  should  be  directed  against 
and  under  the  investment,  and  the  heat  uniformly  raised  to  a 
temperature  that  will  melt  the  solder  without  pointing  the  flame. 
This  is  especially  necessary  in  the  soldering  of  gold  crovims  with 
porcelain  fronts,  also  dummies,  as  the  solder  if  the  investment  is 
properly  placed  flows  by  gravitation  into  the  interstices  between 
the  porcelain  and  the  caps,  and  gives  continuity  of  structure  to 
the  crown.     When  the  solder  has  filled  the  interstices,  the  flame 
may  be  pointed  for  a  moment  to  guide  it  to  some  desired  point. 
A  large  piece  of  charcoal,  concave  on  the  side  to  be  used,  and 
the  other  side  invested  with  a  thin  covering  of  plaster,  furnishes 
a  good  soldering  support,  as  it  retains  the  heat.     A  hand  gas 
blow-pipe,  operated  by  a  foot  bellows,  and  so  constructed  that 
the  flame  is  under  perfect  control,  is  the  most  suitable  (Fig.  649). 
The  Use  of  Borax. — In  soldering  invested  sections  of  cro-vm- 
or  bridge-work,  borax  which  has  been  reduced  to  a  vitreous  state 
by  heat  and  then  finally  pulverized  is  the  preferred  form  for  use. 
Prepared  in  this  manner  it  should  be  sprinkled  on  the  part  pre- 
vious to  the  commencement  of  the  soldering,  and  a  little  added  at 
any  time  it  is  needed  during  the  continuance  of  the  process.-^ 

In  small,  fine  soldering  of  invested  or  uninvested  work,  the 
lump  borax  ground  with  water  on  a  slab  to  a  cream-like  con- 
sistence, and  applied  with  the  point  of  a  stick  or  brush  only  where 
it  is  desired  to  have  the  solder  flow,  is  the  most  suitable.     In 

^Dr.  Parr's  "prepared  flux,"  a  finely  pulverized  vitrified  flux,  can  be  used  in 
this  manner.  It  is  also  prepared  in  combination  with  wax  cement.  In  the  melt- 
ing out  of  the  wax  when  the  case  is  invested  and  heated  for  soldering,  the  llux  is 
carried  into  the  interstices. 


356  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

open-flame  soldering, — for  instance,  where  solder  is  to  be  flowed 
only  on  the  external  surface  of  a  cap  or  collar  by  holding  in  the 
Bunsen  flame, — dampened  calcined  marble-dust  applied  in  a  thin 
layer  on  the  inner  surface  of  the  cap  or  collar  will  prevent  the 
solder  from  flowing  there.  The  marble-dust  is  afterward  easily 
washed  out,  which  is  not  the  case  with  whiting,  which  is  often 
used  for  this  purpose. 


CHAPTEK    V. 

INSTKUMENTS  AND  APPLIANCES. 

The  dentist  who  intends  to  engage  extensively  in  crown-  and 
bridge-work,  and  who  desires  to  practice  it  conveniently  and  suc- 
cessfully, should  supply  himself  with  all  the  necessary  instru- 
ments, tools,  and  other  appliances.     These  consist  principally  of: 

Suitable  drills  and  burs,  including  three  or  four  sizes  of  the 
Gates-Glidden  for  root-canals;  root-trimming  and  shaping  instru- 
ments. Gem  and  corundum  wheels  and  points,  and  rubber  and 
corundum  disks  (see  page  35). 

Pliers  for  shaping  collars  (see  page  67),  and  a  pair  of  excising 
forceps. 

Soldering  clamps  (see  page  85)  and  hand- vise. 

Small-pointed  shears. 

Round  and  half-roimd  plate  files,  very  finely  cut. 

A  small  anvil. 

Bunsen  gas-burner  and  spider  attachment  for  heating  invest- 
ments for  soldering. 

A  gas  blow-pipe  with  bellows,  and  a  mouth  blow-pipe. 

Charcoal  soldering  block. 

Calcined  marble-dust. 

Sulfate  of  potassium. 

Melotte's  moldine  and  fusible  metal. 

Wax  cement  (resin  two  parts,  wax  one  part),  or  Parr's  fluxed 
wax. 

Dies  for  forming  gold  caps  for  use  in  constructing  crowns  and 
capping  dummies. 

Copper  plate  l^os.  34  to  35  gauge,  copper  wire  No.  30  gauge, 
fine  iron  binding  wire,  and  heavy  iron  wire  to  encircle  invest- 
ments. 

Pure  gold  plates  'Nos.  28  to  30  gauge,  22-carat  gold  plate  ITos. 
28  and  30  gauge,  and  18-  and  20-carat  gold  solder. 

Platinum  plate  Nos.  30  and  32  gange  for  collars,  both  heavy 

357 


358 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


and  very  light  platinum  foil  for  backings,  and  some  platinum  and 
iridio-platinum  wire  ISTos.  15  and  17  gauge  for  posts,  and  fine  plati- 
num wire  for  pins  in  either  gold  tips  or  crowns. 


:FiG.  650. 


Fig.  651. 


A  small  assortment  of  cross-pin  plate  teeth  of  light,  medium, 
and  dark  shades,  consisting  of  incisors,  cuspids,  and  a  few  bicuspid 
and  molar  fronts  for  dummies. 


INSTRUMENTS  AND  APPLIANCES.  359 

A  small  rolling-mill  for  plate  will  be  quite  an  acquisition,  as 
gold  scraps  can  be  remelted  and  formed  into  plate. 

The  bench  on  which  the  principal  parts  of  the  work  are  done 
should  be  specially  designed  and  reserved  for  it.  It  should  be 
in  the  same  room,  and  conveniently  situated  a  little  behind  the 
dental  chair,  out  of  view  of  the  patient.  Everything  connected 
with  this  bench  should  be  kept  in  order  and  ready  for  immediate 
use.  Such  a  bench,  made  of  oak  or  black  walnut,  with  a  top  that 
can  be  closed  when  not  in  use,  making  an  unobjectionable  piece  of 
furniture,  is  represented  in  Figs.  650  and  651. 

An  office  lathe  should  be  kept  next  to  the  bench,  or  a  small 
lathe-head  can  be  mounted  on  the  bench  and  operated  by  the 
aid  of  an  electric  motor. 


INDEX. 


Abrasion    of   incisive   edges   of   teeth, 
91. 
method  of  forming  crown  for,  82,  91, 

106,  206,  253. 
method  of  forming  tip  for,  128. 
Abscess,    chronic    alveolar,    treatment 

of,  30. 
Acid,   arsenious,  its  use  and  action  in 

devitalizing  pulps,  17. 
Acid    secretions,    platinum    unaffected 

by,  73.  95. 
Adaptation  of  gold  collars,  67,  103,  112. 
to  porcelain  crowns,  method  of,  58. 
Adjuster    for    use    in    cementation    of 

crowns,  137. 
Adjustment  of  finished  bridge-work  in 

the  mouth,  160. 
Adjustment  of  seamless  crowns,  102. 
Alexander's    method    of    forming    gold 

Inlays  and  tips,  129. 
All-gold  bridge-work,  164,  166,  287. 
All-gold  collar  crowns,  83,  90,  98,  291. 
Alloy   for   forming  any  grade   of  gold 

solder,  348. 
Alloys  of  tin,  their  use  in  crown-work, 

352. 
Alveolar  abscess,  classification  of,  31. 

treatment  of,  30. 
Amalgam,  use  of  in  bridge-work,  176. 

in  crown-work,  39,  48,  141. 
Ames's  method  of  forming  gold  inlays, 

127. 
Amputation  of  the  apex  of  a  root,  33. 
Analysis  of  dentin,  11. 
Anatomical  structure  of  dentin,  10. 
Anchorage    bars    in    bridge-work,    152, 
156,  165,  167,  176,  179,  182,  187. 
manner    of    attaching    to    the    abut- 
ments, 152. 
manner  of  forming,  152,  179,  181,  299. 
Anchorages  or  abutments   for  bridge- 
work,    preparation    of,    150,    169,    173, 
174,  176,  179,  184,  189,  235,  247,  299. 
Dr.   Litch's  method,   249. 
Dr.    Winder's,    246. 
shell,  166,  169,  174,   190. 
Ancient  bridge-work,  145. 


Anesthesia  in  pulp-extraction,  15. 
Anesthetics,    local,    for    application    to 
gum,  31,  72. 
use  of  in  crown-work,  72. 
Antagonizing     teeth,     preparation     of 

their  cusps,  38. 
Antiseptic   agents  in   treatment  of   al- 
veolar  abscess,   24,   33. 
in  treatment  of  pulpless  teeth,  24,  33. 
Anvil,  use  of  in  crown-work,  71,  104. 
Aristol,  use  of  in  pulp-canal,  26. 
Arsenious   acid,    use    of    in    devitaliza- 
tion of  the  pulp,  17. 
Articulation   for   bridge-work,    manner 

of  taking,  152,  294. 
Artificial  crown-work,  9,  43,  327. 

the  gold  system,  66. 
!     the  porcelain  system,  44. 
Artificial     gum     in     porcelain     bridge- 
work,  339. 
j  Attachments     for     removable     bridge- 
I         work,  117,  217,  236,  243,  246,  269. 

Backings     for     porcelain     fronts     in. 
crown-   or    bridge-work,    76,    79,    115, 
j         155,  164.  293. 
j  Baldwin's  method  of  mounting  crowns, 

62. 
j  Bar  bridge-work,   151,   161,   165,   166,   167, 
179,   198,  250,   269,   299,   339. 
advantages  of,  178,  182. 
anchoring  of  the  bar,  179,  181. 
cast  filling  to  support,  127,  182,  196. 
extension,  181. 

in  bicuspids  and  molars,  180. 
in  incisors  and  cuspids,   180. 
Bars  for  bridges,  127,  156,   179. 
Beers's  crown,   66. 
Bing's  bridge-work,  146. 
Blind  abscess,  treatment  of,  31. 
Blow-pipes,   Lee's,    354. 

Knapp's  carbo-oxyhydrogen,  278. 
Bonwill,  Gates-,  porcelain  crowns,  45. 
Bonwill's  removable  plate  bridges,  267. 
Borax,  method  of  using  in  crown-  and 
bridge-work,    in    constructing  root- 
caps  and  tubes,  218,  355. 

361 


362 


INDEX. 


Bridge-work,  145. 

adjustment  and  insertion,  160,  171. 

an  impartial  criticism  of,  147,  176,  214. 

as  affecting  hygienic  condition  of  the 
mouth,   214. 

cantilever,  177. 

cases  illustrating  the  application  of, 
189,   296. 

cementation  of,  133,  137,  161,  171. 

connecting  sections  with  bars,  167, 
189,  224,  240,  261. 

construction  of,  151,  161,  163,  173,  179, 
189,  275. 

detachable,  37,  217,  243. 

extension,  172. 

extensive  application  of,  200. 

foundations  for,  150,  165,  169,  172,  178, 
183,  189. 

general  application  of,  189. 

how  to  cement  any  form  so  it  is 
easily  removed,  137. 

manner  of  taking  impression  and  ar- 
ticulation for,  152,  161,  173,  189,  226, 
234,  294. 

mechanical   principles   governing  the 

'  process  of  construction,  150,  161,  163, 
173,  178,  189,  275,  294. 

Tnethod  versus  to  forming  self- 
cleansing  spaces,  156. 

methods  in  pyorrhea,  191. 

partial  cap  and  pin,  183,  190,  196. 

plate,  234. 

porcelain,  335. 

removable,  216,  234. 

removal  of,  212. 

selection   of   abutments,    150,    172,    179, 
183,  189. 
Bryant's    method    of    repairing    frac- 
tured porcelain  fronts,  211. 

Cantilever  bridge-work,  177. 

crown,   123. 
Cap  for  collar,  to  construct,  75,  84,  113, 
290. 
for  porcelain  crown,  58,  82,  113,  118. 
for  porcelain  fronts  for  bridge-work, 
151. 
Capping  pulps,  methods  of,  12. 
Cast  fillings,  127. 
to   support   bridge-work,   127,   129,   182, 
196. 

Cataphoresis,  use  of,  15,  72. 
Cement,  133. 

oxyphosphate  and  gutta-percha  com- 
bined,  140. 

to  cause  gutta-percha  to  adhere,  139. 

to  cause  oxyphosphate  to  adhere  to 
tooth-structure,   170. 


Cement,  to  cause  to  set  slowly,  134. 
Cementation  of  crown-  or  bridge-work, 
lb3,   161,   171. 
to  be  easily  removed,  137,  140. 
Chronic  alveolar  abscess,  30. 
Circulation  in  dentin,  10. 
Clamps,  soldering,  69,  85. 
Cleansing   of   bridge-work  when   worn 

by  patients,  214. 
Cocain,  use  of,  IS,  17,  72. 
Collar  contractor,  71,  105,  285. 
Collar  crowns,  66. 
bicuspids  and  molars,  83,  95,  99,  287. 
hygienically  considered,  57,  73. 
incisors  and  cuspids,  58,  74,  111,  327. 
Collar  expander,  70,  104. 
Collar  pliers,  67. 

Collars,  method  of  adaptation  of  seam- 
less crowns,  93,  102. 
to  solder,  69,  71,  105. 
Collars  for  crowns,  58,  68,  112,  280,  287. 
construction  and  adaptation  of,  58,  66. 
Townsend's  fusible  die  in  forming,  58. 
Connecting    bars    in    bridge-work,    167, 

189,  224,  240,  261. 
Construction    of    bridge-work,    151,    161, 
163,  173,  179,  189,  275. 
detachable    and    removable,    217,    234, 

246. 
mechanical  principles  governing,  150, 

161,  163,  173,  178,   189,  275,   294. 
plate,  234. 

saddles,  173,  175,  229. 
small  pieces  of,  161,  189. 
special  processes  and  appliances   in, 
163. 
Corundum-wheels  and  points,  36. 
Criticism   of  crown  and  bridge  opera- 
tions, 57,  73,  176,  177,  183,  185,  200,  208, 
335. 
Crown-     and     bridge-work     combined 
with   operative   dentistry  in  dental 
prosthesis,    296. 
instruments  and  appliances,  357. 
Crowns,  artificial: 
Baldwin's  method  of  mounting,  62. 
Bonwill,  Gates-,  45. 
Bonwill  cap,  63. 
Chupein,  112. 
Evans  gold,  99. 

Evans's  pin  and  disk  method,  113. 
Farrar's  cantilever,  123. 
Fillebrown's,  173. 
Foster,  49. 
Gates-Bonwill,  45. 
Hollingsworth,  287. 
Howland-Perry,  49. 
Kirk's  method  of  mounting,  61. 
Leech,  117. 


INDEX. 


363 


Crowns,    urtillcial; 

Lltch,  95. 

Logan,  50. 

Parker's,  97. 

Parr,  116. 

Patrick,  SO. 

Perry,  118. 

Perry-Howland,  49. 

Richmond,  74. 

Rynear,  90. 

Simplicity,  Stowell's,  63. 

Stowell's     metliod    of     mounting,  64, 
80. 

Van  Woert,   110. 

White's,  61. 

all-gold,  in  sections,  S3,  90,  '280. 

attachments   for   all-gold   and    seam- 
less gold,  39,  IDS,  277. 

cementation,  process  of,  48,  55,  133. 

contouring  of  crowns  and  collars,  83, 
98,   99,  101,  282,  284. 

contraction  of,  71,  98,  105,  282. 

dies  for  use  in  construction  of,  79,  84, 
86.  90,  91,  94,  96,  98,  101,  109. 

expanding,   72,   101. 

finishing  and  polishing,  133. 

for  abraded  teeth,  82,  92,  128. 

for  separate  molar  roots,  123. 

gold    and    porcelain,    for    teeth    with 
living  pulps,  82,  331. 

gold  and  porcelain,  without  a  collar, 
111. 

gold  collar,  59,  66,  281,  287. 

gold  seamless  cap,  93. 

gold  seamless  contour,  99. 

mandrel  system,  280. 

partial.  125,  325. 

porcelain,  with  collar  attachment,  58. 
80,  lis. 

porcelain,    with    rubber    attachment, 
65. 

preparation   of  crown  or  root  for,   9, 
35. 

process    of    adjustment    of   gold   con- 
tour, seamless,  102. 

remarks  on  the  use  of  collar  or  por- 
celain crowns,   57,  73. 

removal  of,  212. 

repair  of,   107,   213. 

shell,  169,  170,  174,  190,  194,  196. 

temporary,  65. 
Curtis  removable  bridge,  271. 
Cusps  of  antagonizing  teeth,  prepara- 
tion of,  38. 

Davenport  removable  plate  bridge- 
work,  242. 

Decayed  roots,  special  preparation  of 
for  crown-work,  38. 


Dentin,   circulation  in,  10. 

chemical  analysis  of,  11. 
Detachable    bridge-work,    139,    216,    230, 

246. 
Detachable  porcelain  front,  186. 
Devitalization  of  pulps,  10,  15. 

by  cataphoresis,  15. 

heroic  or  instantaneous,  15. 

use  of  arsenic  for,  16. 

use  of  cocain  in,  15,  17. 
Die-plate,  87. 
Dies.  58,  78,  84,  86,  90,  93,  101,  109,  352. 

Dr.    Melotte's    method    for    forming, 
352. 

counter,  82,  91,  94. 

fusible  metal,  352. 
Diseased    pulps,    classification    of,    re- 
quiring extirpation,  12. 
Diseased  teeth  or  roots,  badly,  9. 

with  necrosis  of  alveoli,  9. 
Disinfection    of    root-canals    and    den- 
tin,  22,   30. 
Disks,   forms   of,   36. 
Drills,     Gates-Glidden.     form     of     and 

method   of   using,   21. 
Dummies,  definition  of,  153.  157. 

how  to  form,  154.  163.  166. 

how  to  form  of  solid  gold,  108,  163. 

how  to  form  hollow,  of  gold,  166. 

how  to  form  in  one  continuous  piece, 
248,   294. 
Dwinelle's    crown,    66. 

English  bridge-work,  146. 
Evans  gold  crowns.  99. 

method  of  inlaying  with  Jenkins  por- 
celain,  331. 

method  of  constructing  all-gold  dum- 
mies in  bridge-work.  lOS,  166. 

non-fusible  crown,   99. 
Erosion,  use  of  porcelain  inlay  in,  326. 
Excision  of  natural  crown,  15,  36. 

and  instantaneous  extirpation  of  the 
pulp,  15. 

when  to  avoid,  11. 
Expansion  of  a  collar  or  crown.  71,  104. 
Extension  bar-bridge.  181. 
Extension  bridges,  173. 

leverage  in.  177. 
Extirpation  of  pulps,  15. 

Facing,    porcelain,     for    gold    crowns, 
75,  79,  115,  331. 
removable  and  replaceable.  186. 
Farrar's  cantilever  crown,   123. 
Ferrules  for  root-crowns,  58,  66,  74,  112. 
Files  for  trimming  roots  or  crowns,  36. 
Fillebrown's  crown,  173. 
Filling  of  root-canals,  27. 


364 


INDEX. 


Finishing    and    polishing    bridge-work, 
133,  160. 
crown-worlc,  133. 
Flange  to  better  support  a  porcelain- 
faced  gold  crown,  90,  112. 
to  better  support  bridge-work,  176. 
Forceps   for    excising   natural   crowns, 
16. 
for  removing  crowns,  212. 
for  repairing,  208. 
Formulas  for  fusible  metals,  352. 
for  gold   solders,   348. 
for  platinum  solder,  341. 
Foster  crown,  49. 
Foundations   for   bridge-work,   150,   172, 

179,  183,  189. 
Fracture  of  porcelain  teeth  in  solder- 
ing, 351. 
Fractured   teeth   and   roots,    treatment 

of  for  crowning,  120. 
French  bridge-work,  146. 
Fusible  alloys  of  tin,  .352. 

Melotte's,  352. 
Furnaces  for  fusing  porcelain,  320,  342. 

Gartrbll,  bridge,  269. 
Gates-Bonwill  crown,  45. 
Gold,    all-,   crowns  for   front   teeth,    90, 
98,  292. 

hollow  dummies  for  bridges,  166. 

molar  teeth,  S3,  95,  99,  280,  287. 

solid,  108,  163. 
Gold    cap-crown,    to    securely    attach, 

39,  109,  277. 
Gold  collar  crowns,  58,  66.  280,  285. 

preparing  natural  teeth  for.  9,  ,35. 
Gold  crown  cutter,  212. 
Gold  crown,  repair  of.  107.  208. 
Gold  cusps  for  bridges  in  one  continu- 
ous piece,  248,  294. 
Gold  cusps,  solid,  79.  86.  156,  263. 
Gold  plate  lined  with  platinum,  67,  347. 

crown-metal,  67,  347. 

solder  filings.  68,  106,  .350. 

solders,  formulas  for,  348. 

standard    of    carat    and    gauge    re- 
quired,  67,   347. 

tips   for   natural   crowns,    method   of 
constructing,  128,   296. 

wire,  218,  275,  348. 
Gold  plates  and  solders,   347. 
Gold  seamless  contour  crowns,  99. 

adjustment  of,  102. 
Gutta-percha,   137. 

combined     with     oxyphosphate     for 
cementation,  140. 

in  filling  root-canals,  27. 

in  preparation  of  roots,  38,  45. 


Gutta-percha,  use  of,  for  cementing 
crown-   and  bridge-work,   137,   161. 

Hbat,   use  of  as  a  disinfectant,  12,  24. 
Hollingsworth's  system  of  crown-  and 

bridge-work,  287. 
Hollow   all-gold   dummies   for   bridges, 

166. 
Hollow  wire  for  posts,  75,  117,  218. 
How   screws,   47,   49. 
Howland-Perry  crown,  49. 
Hub-mold,    88. 
Hygienic    condition    of    the    mouth    as 

affected  by   bridge-work,    214. 
Hygienic       consideration       of       collar 

crowns,  57,  73. 
Hygienic  preparation  of  the  mouth,  9. 

Impressions  of  crowns  or  roots,  45,  56, 
77,  83,  85,  90,  93. 
cups  for  taking,  83,  93,  353. 
for  bridge-work,  152,   161,  173,   189,  224, 

234,  353. 
materials  for  taking,  77,  85,  152. 
Impression  and  articulation  combined, 

152. 
Insertion    and    cementation    of    crown- 

and  bridge-work,  133,   161,  171. 
Instantaneous  extirpation  of  the  pulp, 
15. 
knocking  out  of  the  pulp,  15. 
Instruments  and  appliances,  357. 
Investments  for  soldering,  354. 
in  bridge-work,   158,  354. 
in  crown-work,  17,  115,  354. 
Iodoform,  methods  of  using,  28. 
Iridio-platinum    wire   for   posts,    39,    75, 

348. 
Irregularities  of  the  teeth,  methods  of 

crowning  in,  124. 
Isinglass  (mica),  use  of  in  crown-  and 
bridge-work,  79,  156. 

Kingsley's  method  of  forming  all- 
gold  crowns,  85. 

Kirk's  method,  61,  141. 

Knapp's  methods  in  crown-  and 
bridge-work,  275. 

Land's    method    in    partial    porcelain 

crown-work,   326. 
Lead  counter-dies,  method  of  forming, 

84,   86,  94,   97,   353. 
Leech's  crown,  117. 
Leverage   in  bridge-work,   150,    177,   181, 

200. 
in  extensive  bridge-work,  200. 


INDEX. 


■6^)0 


Litch's  method  of  crowning,  95. 
detachable  bridge,  249. 
partial  cap  and  pin  bridge,  183,  196. 
Logan  crown,  50. 

method  of  mounting  with  band  and 

cap,   58. 
Dr.    Baldwin's   method   of   mounting, 
62. 

Mandrel  system,  280. 
Mandrels   for    forming   collars,    70,    280. 
Mason  replaceable  fronts,  187. 
Materials      and      processes      used      in 
crown-  and  bridge-work,  345. 
molds  and  dies,  352. 
porcelain  teeth,  351. 
soldering,  354. 
Measuring  the  size  of  necks  of  crowns 
or  roots  for  collars,  69,  282,  287. 
natural    crowns   or   roots   for    ready- 
made  gold  crowns,  102. 
Melotte's  method,  153,  352. 
metal,  352. 

method  of  making  model  and  articu- 
lation in  constructing  bridge-work, 
153,  353. 
moldine,  352. 
Metal  flange  to  support  crown,  94,  112. 
Metallic  dies  and  counter-dies,  352. 
Metallic    dies    for    forming    caps    with 

cusps  for  crowns,  84,  352. 
Models   for   bridge-work,    152. 
Molar  roots  decayed  apart,  method  of 

crowning,  123. 
Moldine,  352. 
Molding,    methods   and  materials   used 

in,  79,  84,  93,  100,  352. 
Molds  and  dies,  352. 
Morey  bridge,  269. 
Morrison's  crown.  66. 
Mouth,  preparation  of,  5,  9. 

Necks  of  teeth,  average  forms  of,  68. 
methods  of  measuring,  69,  282,  287. 

Objections     urged      against     bridge- 
work,  147. 
against  collar  crowns,  73. 
against  porcelain  crowns,  57. 
Obtundents,    use    of    in    alveolar    ab- 
scess, 31. 
use  of  in  crown-work,  72. 
use  of  in  extirpation  of  pulp,  15. 
Ottolengui  root-reamers  and  facers,  53. 
Oxyphosphate  cement,   133. 
properties    suitable    for    crown-work, 

133. 
to  cause  to  set  slow,  134. 


Parker  gold  crown,  9?. 

Parr's  crown,  116. 

Parr's      detachable      and      removable 

bridge-work,  256. 
Partial  crowns,  gold,  125. 

Dr.  Land's  method,  326. 

Dr.  Littig's  method,  131. 

porcelain,   327. 

porcelain  and  gold,  89. 
Patrick's  cap-stamping  machine,  98. 

crown-work,  89. 

formula  for  gold  for  collars,  347. 
Perforation  of  side  of  root,  treatment 

of,  122. 
Perry's  crown,  118. 

Pin-  to  attach  gold  crown,  109,  127,  277. 
Pin-bridge,  partial  cap  and,  183,  196. 
Plaster    impression    and    articulation, 

method  of  taking,  152,  161,  173,  189. 
Plate  bridge,  234. 

removable,  234,  263. 
Plates  and  solders,  347. 
Platinum  plate,  348. 

advantages  in  crown-work,  67,  73,  95, 
113,  127. 

and  gold,  67. 

solder,  341. 

wire,  67. 
Pliers  for  shaping  collars,  67. 
Polishing-    and    finishing    crown-    and 

bridge-work,  133,  158. 
Porcelain,     advantages    of    for    inlay- 
work,  311. 

artificial  teeth,  use  of  frr  inlay-work, 
324,   326,  334. 

comparative   fusing  points  of  differ- 
ent, 334. 

erosion,  use  of,  for,  326, 

heat  effect  on  color  of,  319. 

shrinkage   of   in   fusing,    320,   321,    323. 
Porcelain  crowns,  44. 

Foster,  49. 

Gates-Bonwill,   45. 

Howland-Perry,   49. 

Logan,  50. 

method   to   facilitate   the   adaptation 
of  to  the  root,   44,   56. 

remarks  on  the  use  of,  57. 
Porcelain    and    gold   crown   without   a 

collar.  111. 
Porcelain  dental  art,  307. 
Porcelain  bridge-work,  335. 

adaptation  of  s.addle  for,  337. 

cementation  of,  339. 

criticism  of,   335. 

formation   of   dummies,   336. 

frame-work    of,     strength     required, 
335. 


Wj&, 


366 


INDEX. 


Poi'celain  bridge-work,  proper  and  im- 
proper forms  of  construction,  3B5. 
solder  required  for,  338,   341. 
Porcelain   crown   with   gold   collar    at- 
tachment, 58,  80,  118. 
Porcelain    faces    for    bridge-work,    154, 
186,   295. 
for  crowns,  75,  115,  155,  293,  296. 
Porcelain   fronts,    backing   for,    75,   115, 

155,  293,  296. 
Porcelain  inlays,  cavity  preparation  of 
for,   311. 
cementation  of,  322. 
dies    or    molds    for    shaping    matrix, 

317,  323. 
former  and  present  methods,  310. 
furnaces  for  fusing,   320,   342. 
fusing  or  baking  of,  320,  321,  342. 
gassing  of,  342. 

high-  and  low-fusing  body  for,  333. 
matrix,    application   of  body   to,   for, 

319. 
matrix,  investment  of,   for,  317. 
matrix,  shaping  and  removal  for,  314. 
matrix,   metal  used  to  form,   for,  314. 
points    to    bear    in    mind    regarding, 

323. 
selection  of  shade  of  body  for,  318. 
Porcelain  and  platinum  crowns,  327. 
incisors  and  cuspids,  327,  328. 
bicuspids,   329. 
jacket  crown,  328. 
tube  crown,  330. 
Porcelain     method     of     inlaying     gold 
crowns  with  Jenkins  porcelain,  331. 
Porcelain  partial  crown-work,  325. 
Porcelain  teeth,  selection  of,  351. 
some  causes  of  fracturing  in  solder- 
ing, 351. 
veneers  of,  351. 
Porcelain   tips   to  natural  crowns,   130, 

325. 
Posts   for   retaining  crowns,   39,   46,    75, 

109,  111,  113,  117,  277. 
Pouring  fusible    alloy   or   metal,    man- 
ner of,  84,  97. 
Preparation     of     natural     crowns     or 
roots  for  gold  crown-work,  35. 
for  Logan  crown,  50. 
for  porcelain  crowns,  37,  50. 
Preparation,  special,  of  badly  decayed 

teeth  and  roots,  38. 
Preparatory  treatment   of  the   mouth, 

6,  9. 
Pulp,  capping  of,  12. 
diseases  cf  requiring  extirpation,   12. 
instantaneous      devitalization,      with 
excision  of  crown,  15. 


Pulp,  lesions  of,  12. 
preservation  or  devitalization,  10. 
use  of  arsenic  in  devitalization  of,  17, 
18. 
Pulpless    teeth,    their    treatment    and 

disinfection,  19. 
Punch  forceps  for  riveting,  for  use  in 

repairing  bridge-work,  208. 
Pyorrhea    alveolaris,     bridge-work    in 
cases  of,  191. 
collar  crowns  in  cases  of,  73,  191. 

Ready-made  crowns,  the  Evans,  99, 

the  Rynear,  90. 
Reaming  of  root-canals,  21,  52,  75,  113. 
Removable    and   replaceable   porcelain 

fronts,  186. 
Removable  bar-bridges,  269. 
Removable  or  detachable  bridge-work, 
216,  234,  246. 
Alexander's  method,  248,  257. 
Dr.  Curtis' s  method,  271. 
Dr.   Litch's,  249. 
Dr.   Morey's,  269. 
Dr.  Parr's,  256. 
Dr.  A.   S.   Richmond's,   229. 
Dr..  Starr's,  251. 
Dr.  Waters' s,  264. 
Dr.  Winder's,  246. 
connecting  bars  for,  225,  240,  261. 
Removable    crowns    and    attachments 

for  bridge-work,  217,  234,  246,  269. 
Removable  plate  bridges,  234,  261. 
Dr.  Bonwill,  267. 
Dr.  J.  L.  Davenport,  242. 
Dr.  Parr's  methods,  261. 
Dr.  Waters's  methods,  263. 
Removal    of   crown-   and   bridge-work, 

212. 
Repair  of  crown-  or  bridge-work,  208. 
Dr.  Bryant's  method,  211. 
Dr.  Shriver's  method,  209. 
Dr.  Starr's  method,  210. 
Dr.  Williamson's  method,  210. 
Repair  of  gold  crowns,  107,  213. 
Retaining-pin    for    all-gold    crown,    39, 

109,    277. 
Richmond  crown,  the  original  form  of, 

introduced,  74. 
Rod    method    of    porcelain    inlays,    310, 

325. 
Root,  method  of  filling,  27. 
method  of  treatment,  19. 
Root-canal,       antiseptic      agents      for 

treatment  of,  24. 
Root-drier,  24. 

Root-reamers  and  facers,  Ottolengui's, 
52. 


INDEX. 


367 


Root-trimmers,  iiti. 
btarr'a,  :i54. 

Roots  intervening  between  abutments, 
Iby,  231. 
special     preparation     of     badly     de- 
cayed, 3S. 

Rubber    or    vulcanite    attachment    for 
crown,  65. 

Rules      governing      the      insertion      of 
bridge-work,  150,  in,  ITtl,  177,  189,  2uu. 

Rynear's  crown,  90. 

Screws  to  support  crowns,  46,  61,  63. 
Seamless  gold  collars,  280. 
Seamless  gold  crowns,  93,  99. 
method  of  contouring,  99. 
method  of  forming  from  an  impres- 
sion, 95. 
process  of  adjustment  and  insertion, 
102. 
Self-cleansing    spaces    in    bridge-work, 

155,  156. 
Sensitive  dentin,  treatment  of,  13,  37. 
Shapes  of  necks  of  teeth,  68. 
Shaping  teeth  and  roots  for  crowning, 

process  of,  35. 
Shell  anchorage  or  crown,  169,  190. 
seamless,  170. 
how  to  cement,  171. 
Shoulders    on    the    anterior    teeth,    92, 

163. 
Slots  for   anchorage  bars,   152,   165,   166, 

178,  198,  299. 
Solder,   gold,   formulas  for,   347. 
Soldering,   manner  of,   77,  79,   81,  84,   86, 
90,   105,   115,   127,   156,   290,   354. 
investments  for,  354. 
Solid  gold  crowns,  68,  164. 
Special  forms  and  methods  in  crown- 
and  bridge-work,  58,  111,  163,  183,  246, 
269,  275,  280,  287. 
Dr.  Alexander's,  129,  196,  248,  257. 
Dr.   Bonwill's,  267. 
Dr.   Curtis' s,  271. 
Dr.  Knapp's,  275. 
Dr.   Litch's,  249. 
Dr.  Morey's,  269. 
Dr.  Parr's,  256. 
Dr.  Spencer's,  248. 
Dr.  Starr's,  251. 
Dr.  Waters's,  264. 
Dr.   Winder's,   246. 
mandrel  system,  280. 


Special   preparation   of    badly   decayed 

teeth  or  roots,   38. 
Spur  support  in  bridge-work,  176,  189. 
stamping  press  for  caps,  100. 
Starr's   method   of   detachable    bridge- 
work,  251. 
root-trimmers,  269. 
Sterilization  of  root-canals,  24. 
Stowell's  porcelain  gold  collar  crowns, 
80. 
Simplicity  crown,  63. 
Strengthening    gold    seamless    crowns, 

106. 
Sulfuric  acid,  care  in  the  use  of,  33. 

use  of  in  cementation,  171. 
Syringes,  hot-air,  23. 
abscess,  30. 

Teeth,  porcelain,  351. 

porcelain  veneers,   £51. 
Temporary      attachment      of      bridge- 
work,  161. 
Temporary  crown,  65. 
Thickness  of  plate  suitable  in  crown- 
work,  67,  347. 
Tin,  alloys  of,  352. 
Tips,    porcelain    or    gold,    for    natural 

crowns,  128,  325. 
Townsend's    fusible    die    for    forming 

collars  for  porcelain  crowns,  58. 
Treatment    of    chronic     alveolar    ab- 
scess, 30. 
preparatory,  of  the  mouth,  9. 
Trimmers,  root-,  36. 

Starr's,  254. 
Trying  in  bridge-work,  154,  161, 

Van  T\''oert's  crown,  110. 

Warping  of  bridge-work  in  soldering, 
159. 

Waters's  removable  bridge-work,  264. 

Wheels  for  shaping  natural  crowns 
and  roots  for  crown-  and  bridge- 
work,  35. 

White's  method  in  crown-work,  61. 

Winder's  detachable  bridge-work,  246. 
Dr.  Spencer's  method  in,  245. 

Wire  for  posts  or  pivots,  39,  46,  61,  75, 
109,  217,  348. 

Zinc  oxychlorid,   use  of,   13,  28,   39. 
oxyphosphate   of,   39,   133. 


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